Date posted: April 10, 2012


I. Nature, involvements, and writing of the history of philosophy
The writing of the history of philosophy
Shifts in the focus and concern of philosophy through history

II. Ancient Greek and Roman philosophy
The Pre-Socratic philosophers
Cosmology and the metaphysic of matter
Epistemology of appearance’
Metaphysic of number^
Anthropology and relativism
The seminal thinkers of Greek philosophy

Hellenistic and Roman philosophy
Neo-Pythagoreans and Neoplatonists

III. Medieval philosophy
Early medieval philosophy
Transition to Scholasticism
The age of the Schoolmen
Philosophy in the late Middle Ages

IV. Modern philosophy
The Renaissance and early-modern period
Dominant strands of Renaissance philosophy
Rise of Empiricism and Rationalism
Literary forms and sociological conditions

The Enlightenment
Classical British Empiricism and its basic tasks
Nonepistemological movements in the Enlightenment
Critical examination of reason in Kant
Literary forms

The 19′” century
German idealism of Fichte, Schefting, and Hegel
Positivism and social theory in comte. Miff, and Marx
Independent and irrationalist movements

The 20″‘ century
Individual philosophies of Bergson, Dewey, and whitehead
Marxist thought
Analytic philosophy
Continental philosophy
Concluding comments

“Phylosophy” has meant many different things. Some of these have been a search for the wisdom of life (the meaning closest to the Greek words form which the term is derived) an attempt to understand the universe as a whole; an examination of man’s moral  responsibilities and his social obligations: an effort to fathom the divine intentions and man’s place with reference to them; an effort to ground the enterprise of natural science; a rigorous examination of the origin, extent, and validity of men’s ideas; an exploration of the place of will or consciousness in the universe; an examination of the values of truth, goodness, and beauty; an effort to codify the rules of human thought in order to promote rationality and the extension of clear thinking. Even these do not exhaust the meaning that, have been attached  to the philosophic enterprise, but they give some idea of its extreme complexity and many sidedness.

Thus, although there are a few single-term divisions of philosophy of long standing-such as logic, ethics, epistemology (the theory of knowledge), or metaphysics (theory of the nature of Being)- its division are probably best expressed by-phrases that contain the preposition “of- such as philosophy of nature or philosophy of art.

1. Thomas Aquinas (a Dominican friar of the 13th century), George Berkley (a bishop of the Irish Church in the 18th century), and Soren Kierkegaard (a Danish divinity student in the 19th century) all the saw philosophy as a means to assert the truths of religion and to disel the materialistic or Rationalistic errors that in their opinion, had led to its decline.

2.Pythagoras in ancient south Italy, Rene Descartes in the late Renaissance, and Bertrand Russeli in the 20th century have been primarily mathematicians whose views of the universe and of human knowledge have been vastly influenced by the concept of number and by the method of deductive thinking.

3. Some philosophers, such as Plato or the British philosophers Thomas Honnes and John Stuart Mill, have been obsessed by problems of political arrangement and social living, so that whatever else they have done in philosophy has been stimulated by a desire to understand and, ultimately, to change the social and political behavior of men.

4. Milesians (the first philosophers and of Greece); Francis Bacon, an Elizabethan philosophers and in the 20th century, Alfred North Whitehead, a process metaphysician – have began with an interest in the physical composition of the natural world, so that their philosophies resemble more closely the
generalizations of physical science than those of religion or sociology.

The history of western philosophy reveals in detail the concentrated activity of a multitude of serious and able men reflecting upon, reasoning about, and considering deeply the nature of their experience. But throughout this manifold diversity certain characterize oppositions habitually recur, such as the division between Materialists and Idealists in cosmological theory; between Nominalists and Realists in the theory of signification; between Rationalists and Empiricists in the theory of knowledge; between Utilitarian, self-realizationists, and proponents of duty in moral theory; and between partisans of logic and partisans of emotion in the search for a responsible guide to the wisdom of life.

These two divergent motivations tend to express themselves in two divergent methods: that of analysis and that of synthesis. Plato’s Republic is an example of the second. The Principle Ethics (1903) of G.€.Moore, a founder of linguistic philosophy, is an example of the first.

The analytic, or critical, impulse treats any subject matter or topic by concentrating upon the part, by taking it apart in the service of clarity and precision. The synthetic or speculative impulse operate by seeking to comprehend the whole, by putting it all together in the service unity and completeness. There is one philosophical tradition-that of Positivism – which sees philosophy as originating in the pure sunshine of scientific clarity.

Though Positivism represents a partisan view that it is not necessary to hold, it does express indirectly a basic truth-that the philosophic enterprise has always hovered uncertainly between the lure of religious seriousness and that of scientific exactitude. In the earliest philosophers of Greece, it is impossible to separate ideas of divinity and the human soul form ideas about the mystery of being and the genesis of material change, and in the Middle Ages philosophy was acknowledged to be” the handmaiden of theology”. But the increased secularization of modern culture has largely reversed this trend, and the Enlightenment emphasis upon the separation of nature form its divine creator has increasingly placed philosophic resources at the disposal of those interested in creating a philosophy of science.

Yet philosophy’s continuing search for philosophic truth leads it is to hope, but at the same time to profoundly doubt, that its problems are objective. With respect to a total description of being or a definitive account of the nature of values, only individual solutions now seem possible; and the optimistic hope for objective answers that secure universal agreement must be given up.

In this respect, philosophy seems less like science than like art and the philosopher more like an artist than a scientist, for his philosophic solutions bear the stamp of his own personality, and his choice of arguments reveals as much about himself as his chosen problem. As a work of art is a portion of the world seen through a world subjectively assembled. Plato and Descartes, Immanuel Kant, the pivotal figure of modern philosophy, and John Dewey, a U.S. Pragmatist, have given to their systems many of the quaint trappings of their own personalities,

But if philosophy is not true in the same sense as science, it is not false in the same sense either; and this gives to the history of philosophy living significance, which the history of science does not enjoy. In science, the present confronts the past as truth confronts error; thus, for science, the past, even when important at all, is important only out of historical interest. In philosophy it is different. Philosophical system are never definitively proved false; they are simply discarded or part aside for future use. And this means that the history of Philosophy consists not simply of dead museum pieces but of ever – living classics – comprising a permanent repository of ideas, doctrines, and arguments and a continuing source of philosophical inspiration and suggestiveness to those who philosophize in any succeeding age. It is for this reason that any attempt to separate philosophizing form the history of philosophy is both a provincial act and an unnecessary impoverishment of its rich natural resources.

History of philosophy has been traditionally subject to types of ordering, according to whether it was conceived.

1. As primarily a history of ideas.
2. As a history of the intellectual products of men.

Froedrich Lnage’s Geschichte des Materialisms (1866), Eng.tras The History of Materialism (3rd ed.. 1925), A.C.Ewing’s compilation The Idealist Tradition, from Berkely to Blanshard (1957). or Richard H.Popkin’s History of Skepticism from Erasmus to Descartes (1960). In the second type of ordering, the historian, impressed by the producers of ideas as much as by the ideas themselves – that is, with philosophers as agents – reviews the succession of great philosophic personalities in their rational achievement.

These two different types of ordering depend for their validity upon an appeal to how different principles about the nature of ideas, but their incidental use may also be influenced by social or cultural factors. Thus. the biographers and compilers of late antiquity (among them, Plutarch, Sextus Empiricus. Philostratus. and Clement of Alexandria), impressed by the religious pluralism of the age in which they lived, thought of philosophers, too, as falling into different sects and wrote histories of the Sophists, the Skeptics, the Epicureans, and other such schools; whereas almost 2,000 years later. Hegel-living in a period of romantic historiography dominated by the concept of the great man in history- deliberately described the history of philosophy as ‘a succession of noble mind, a gallery of heroes of thought”.

The type of ordering suggested above also has some relationship to the more general  problems of method in the writing of the history of philosophy. Here there are at least three factors that must be taken into account;

1.The historian must understand how (at least in part) any philosopher’s doctrines depend upon those of his predecessors;

2. He must understand that a man’s philosophy occurs at a certain point of time in history and, thus, how it expresses the effects of certain social and cultural circumstances;

3. He must understand how in part it stems from the philosopher’s own personality and situation in life,

The first factor may be called logical because it is the intellectual response that a given philosophy make to the doctrines of it forerunners in which the very problems taken as central have often been given by the current climate of controversy. Thus, many of the details of Aristotle’s ethical, political, and metaphysical systems arise in arguments directed against statements and principles of Plato.

The second factor may be called sociological because it considers philosophy, at least in part as a direct form of social expression arising at a certain moment in history, dated and marked by the peculiar problems and crises of the society in which it flourishes. Thus, the philosophy of Kant, with all of its technical vocabulary and rigid systematization, may be viewed as an expression of the new professionalism in philosophy a clear product of the rebirth of the German Universities during the 18th century English tenement.

The third factor may be called biographical or individual because with Hegel, it recognize that it philosophers are generally produced by men of unusual or independent personality whose systems usually bear the mark of their creators. The cool intensity of Spinoza’s geometric searches for wisdom, the unsewrving (if opaque) discursiveness of Hegel’s quest for completeness or totality. These qualities mark the philosophical writings of Spinoza. Hegel, and Moore with an unmistakably individual and original character. But in a synoptic view of the history of philosophy, one is particularly aware of the various shifts of focus and concern that philosophy has sustained and, indeed, of the often profound difference in the way that it defines itself or visualizes its task from age to age or form generation to generation.

I. Philosophy among the Greek slowly emerged out of religious awe into wonder about the principles and elements of the natural world. But as the Greek
populations more and more left the land to become concentrated in their cities, interest shifted form nature to social living; question of law and convention and civic values became paramount. Cosmological speculation partly gave way to moral and political theorizing and the preliminary and somewhat fragmentary questionings of Socrates and the Sophists turned into the great positive constructions of Plato and Aristotle. With the political and social fragmentation of the succeeding centuries, however philosoizing once again shifted from the form of civic involvement to problems of salvation and survival in a chaotic world.

11.. The drawn of Christianity brought to philosophy new tasks. Augustine, the philosophic bishop of Hippo, and the Church Fathers used such resources of the Greek tradition as remained (chiefly Platonism) to deal with problems of the creation, of faith and reason and of truth.

111. The waning of the Middle Ages became the Renaissance. Universalism was replaced by nationalism. Philosophy became secularized. The great new fact was that of the mystery and immensity of the natural world. The best philosophic minds of the 17th century turned to the task of exploring the foundations of physical science, and to symbol of their success – the great system of physical science, and to symbol of their success – the great system of Newton’s physics – turned the philosophers of the Enlightenment to epistemology and to the examination of the human mind that the hand produced so brilliant a scientific creation.

IV. The 19th century, a time of great philosophical diversity, discovered the irrational and in so doing prepared the way for the oppositions between analysis and Phenomenology and between Positivism and Existentialism that characterize the present situation in philosophy.

Definition of logic
The terms logic is derived from the Greek word “logos”, which means reason or expression of reason in words that is discourse. Etymologically. therefore, Logic is the science of reasoning or argument According to Dewey and Stebbing, reasoning or reflective thinking is a process of finding way out of some difficulty or problem by weighing the evidence on the basis of a tentive hypothesis and thereby reaching some conclusion. The reasoning can be either deductive or inductive. In the deductive reasoning we argue from a general principle to a particular conclusion. For example if we say that since all men are mortal, and X who is a man is mortal. But if we argue that since X, Y, Z, who are men are subject to death, every man must be subject to death, we are arguing inductive In logic we study the general principles governing both type of reasoning. Accordingly, we may define Logic as the science of taws of thought and reason.

J.S.MiII:- “Logic is the science of operations of understanding which are subsequent to the estimation of evidence of both the process itself of advancing from known truth to unknown and all other intellectual operations in so far as ancillary to this.” The definition by Mill brings out the main characteristics of logic, namely ( i ) logic helps in evaluating the evidence in order to arrive at a proof; (ii) logic helps to discover unknown facts on the basis of known and (iii) logic deals with all intellectual processes pertaining to deduction and induction.

Scope and subject matter of logic
The definition of logic given by Mill clearly indicates the scope of logic. According to Mill, “logic is the science of the operations of the understanding which are subsequent to the estimation of evidence, both the process itself of advancing from known truth to unknown and all other intellectual operations in so far as ancillary to this”. This definition brings our following facts:

(1) That logic studies various intellectual processes such as thinking, reasoning and judgment.
(2) That logic studies processes necessary for evaluating evidence.
(3) That logic studies how to move from known to the unknown. This can be done in two ways: by moving from general to particular, as in the example “All men are rational, Ram is a man, therefore, Ram is rational”, or by moving from particular instances to a general conclusion as in “Apples, bananas, mangoes etc. fall to ground because they are heavy and, therefore, all heavy things must fall to the ground”. The first example illustrates the deductive reasoning while the second illustrates inductive reasoning, and both are within the scope of logic.

(4) That logic studies all intellectual processes involved in deduction and induction.
(a) In deduction we study laws of thought, viz., law of identity, law of non- contradiction and law of exclused middle. We also study the different types
of terms. We also study genus differential and accidental properties of terms. We also study formal rules of deduction, the immediate and mediate inferences. And, finally we study various fallacies in argumentation.

(b) In induction we study the difference between form and matter, the nature of definition, hypothesis, evidence, experimental techniques, probability etc.
We also study rules of classification, taxonomy (giving new names) etc. Finally, we study the fallacies incidental to inductive reasoning.

Importance of logic
Though it is true that the knowledge of rules of logic is no guarantee against false reasoning, this is no serious objection against logic. The worth of any science is to be judged not by its actual practice but by the nature of facts it is about. For instance, the science of medicine is not to be condemned as some doctors fail to diagnose diseases properly. The study of logic cannot ensure that logicians will never^make in argument; but the chance of making mistake is certainly much less in their case.

Logic and psychology
Though there exists a close and strong relation between Logic and Psychology, the two are quite distinct and it is not possible to reduce one to the other or treat logic as a branch of psychology, which primarily deals with thinking and judgment. Again, it will be equally false to assert that since all arguments are decidable by logic principles, psychology is nothing but the logic “of mental process.

A general confusion about the relation of logic and psychology stems from the fact that traditionally logic is defined to be a science of laws of thought but now it is generally accepted that any investigation into the laws or ways in which we actually think belongs to psychology. Logic has little concern as to how^one thinks and arrives at conclusions, -It is only concerned with whether two propositions imply each other and what can be the valid inference, To illustrate: it may not be possible for someone to conceive the existence of mermaids. But irrespective of the fact whether we are able to imagine mermaids or not, logically it is valid to assert, that if there are mermaids then they are females with human head and the body of a fish.

It has been aptly observed by Cohen and Nagel that it is very important to distinguish between logic and psychology if we are to avoid the confusion of logic with certain allied subject which though occurring along with logic are nevertheless very different. The realization that logic cannot be restricted to psychological phenomena, therefore, will help us to discriminate between logic and rhetoric. The rhetoric is an art of persuasion. While it is true that if a ailed argument is put effectively by employing words like ‘indubitably’, beyond a shadow of doubt’, ‘clear as day which do not militate against them no amount of rhetoric can transform an invalid argument into valid. This does not mean that rhetoric is useless. It helps harmonious social relation. But it must be realized that the validity of an argument is quite independent of what goes in our head or how we put it forward. The validity in short is extra human. Therefore, psychology has to bearing upon the essential subject matter of logic, However, psychology does have an important role. It helps us appreciate how the social and personal prejudices block effective argument and also that personal or subjective assurance is no guarantee about the validity of an argument. As Nagel says, “The history of human error shows that the assertion ‘I am absolutely certain’ or ‘I cannot help believing” in regard to any proposition is no adequate evidence of its truth.”

Logic and philosophy
Philosophy is the philosophical process, which deals with certain specific problems from the philosophical viewpoint with the help of philosophical methods and arrives at certain philosophical conclusion. This definition of philosophy, abstract though it is, shows the distinction between philosophy and science. Science is a systematic study of a limited field of experience. Thus philosophy and a science differ in connection with methods, problems, viewpoints and conclusions. The most important branches of philosophy are metaphysics, epistemology and axiology of those logic comes within the fields of axioloav.’ Axiology is the study of values. These values are generally of three kinds – truth, good and beauty. While ethics studies good. aesthetics studies beauty. Logic studies truth. It is the science which discriminates between true and untrue among the oppositions It is the method of arriving at the implication or meaning of propositions- It is the science of the value of truth. Thus logic is a branch of philosophy. Its knowledge is absolutely necessary for a philosopher, though it cannot be said that the logician equally necessarily requires the knowledge of philosophy.
Philosophy depends upon logic, though in its turn logic does not depend upon philosophy.

Phylosophical and Logical method
Logic and philosophy are most intimately related in the field of methods. The two most important methods of philosophical thinking are induction and deduction – the two branches of logic. It is here that philosophy and logic are intimately related since the former depends upon the later. Logic is concerned with the laws of induction and deduction, their merits and demerits and the fallacies to their wrong use. In the absence of logic, the methods of analysis and synthesis cannot be properly used in philosophy. It is hence that Logical Positivism one of the most important contemporary school of philosophy, has considered logical analysis as the chief method of philosophical thinking. This has been admitted by most of the contemporary philosophers. It has been accepted that philosophizing is impossible in the absence of a sound knowledge of logic.

Value of Logic in Philosophy
Thus the relationship or logic with philosophy the same as its relation with science, Every science requires logic for the proper presentation of scientific theory and cultivation of induction and deduction. In the absence of the knowledge of logic proper thinking in the field of philosophy is not possible. Neither can a philosopher arrive at logical conclusions.

Need of Philosophy in Logic
Logic discovers the laws of thought. It is on the basis of these laws that correct thinking is possible. Each science is based upon certain fundamental postulates. For example the law of causation is a postulate in physics. Similarly in logic the fundamental laws of though such as law of non-contradiction, law of identity and law of excluded middle or the law of sufficient cause are postulates, they are not proved but accepted. Logic does not example the truth of, these laws of thought. However this is precisely the function of philosophy. Philosophy examines the fundamental postulates of logic as all other positive and normative sciences. Thus philosophy provides the foundation to logic, therefore, depends upon philosophy.

Thus philosophy and Logic are closely related. According to logical positives, the function of philosophy is to examine the fundamental postulates of all the science and to show as to how far they are valid. It is so since science is limited to the field of facts while critical evaluation is the function of philosophy. This again is the function of philosophy in the fields of logic.                         

Fundamental laws of thought
“Logic has often been defined as the study of ‘Laws of thought’ and in particular three principles:-

(1) The principle of identity.
(2) The principle of contradiction.
(3) The principle of excluded middle.
Besides the above-mentioned three laws, Leibnitz considers Law of sufficient Reason, an additional law.

Law of identity
I. According to this law, if anything is A it is A, or if any proposition is true. In accordance with this we know that in a deductive argument, the meaning of the terms must remain same throughout. For example if we say that since books are meant to be read, the books in a bank must be read, we violate the law of in the usual sense. Heraclitus and Buddhists deny the validity of this law, because, according to them nothing remain same at any two moments.
But this criticism is invalid because there is fundamental difference in the realm of things and the realm of thinking. For instance though we cannot step into the same river again, this assertion itself is either true or false and if true it is true now as it was true when Heraclitus Asserted it. Therefore ideas and natural objects are not subject to same laws.

Meaning of the Law of Identity
The law of identity can be expressed as follows”-

(1) What is. is – It has been pointed out by the author of Bhagwadgita, that whatever exists cannot be non-existent and whatever is non-existent cannot exist. In other words what is, is and what is not, is not.

(2) Each object is equal to itself – Every thing is identical. Each object should be taken as it is. For example a kilogram is a kilogram and a pound is a pound. If we do not stick to their fixed meaning and take each to be identical with itself, we cannot use them for the purpose of thinking.

(3) A thing is what is – The nature of a thing has some fundamental elements, which show its basic properties and functions. For example, if it is said that a man, it may be tautology and yet one means by it that the human nature is like human nature and different form the nature of a thing, animal or God.

(4) Everything is according to itself – Leibnitz has pointed out to a law of identity of indiscernible in his monadotogy. This means that each monad represents only itself and no one else since each monads windowless and develops from within.

Thus in nature one finds different levels of things and living beings. No two things are identical. This is know/n as the law of identity of indiscernibles. In order words, every things is according to itself. Had there been two things of the same nature it would have been better to call them one rather than to. There can be no dualiam without distinction. If there is no distinction between two things they are one. Thus the analogy of a thing is only itself. A lion is a lion and different from all other animals. The only analogy of man is man.

(5) Truth is coherent- Every principle must be explained in consistency with is basic postulate since truth lies in coherence. While examining a philosophical thought it should not be compared with other philosophical thinking since the two are different. In order to examine the truth of a philosophy we have to enquire about its self-consistency. The logical implication of its basic postulate should be the same form the beginning to the end. Otherwise, it is far from consistent. It may be noted here that in that in the field of nature the above-mentioned however law may have certain exceptions. In the realm of thinking however, no such exception is possible.

Value of the Law of Identity
The law of identity does not mean that nothing is chargeable but it insists upon a uniformity and continuity in this change which is responsible for the identity of the object.
Every thing is this world is changeable. But while we think about an object we take it as something is not identical. If a thing is constantly changed, thought upon this thing is not possible,. This may lead to the dilemma that thought is not actually applicable to the changing nature, but in the realm of thought thinking is not possible without acceptance of the law of identity.

Again nothing can be defined without taking recourse to the law of identity. A thing is defined in terms of its properties and nature. Thus, though we may admit with the philosophers like F.H.Bradlley and Henry Bergson that the physical world is the result of the thought and the world of thought does represent the actual world, it must be admitted  that philosophies were not also possible without abstraction. Intact the world of thought should be considered as distinct from the world of things through the two are interrelated. It is them that we will be able to understand that just as the world of physical things follows the law of nature, similarly the world of thought follows the taw of thought.

Law of non contradiction
The law of Contradiction has been expressed as A cannot be B and not B at the same time. In other works, a thing cannot both exist and non-exist at the same time. If you say that Ram is in the house, it cannot be said that the is out of the house. One cannot assert that Ram is both in the house and out of it unless the words, in and out are taken in some special sence. If it means physical existence with in. the same physical existence without is not possible.

Hamilton has called the law of contradiction as the law of non-contradiction. According to him correct thinking is non-contradicted. For example, a thing cannot be white and non white. If a thing exists it cannot be said to be non-existence. In other words either A is B however not-B at the time. Nothing can have contradictory qualities in the same space-time. It is possible that a shield is white on one side and non-white on the other side, but it cannot be white and non-white on the same side. The law of contradiction can be better called the law of non-contradiction since it shows that non-contradiction is a necessary condition for correct thinking. It may be remembered here that though one may find contradictory things in nature, the same is not possible in the world of thought. Coherence,though no virtue of the physical world, is certainly a condition for human thinking.

Law of excluded middle
According to this law anything must be either true or false, i.e. A or not A. For example, a piece of the toffee can either be sweet or not sweet. According to Jeyons, “The very name of the taw expresses the fact that (here is no third or middle course”. Though in a way these laws of thought are related to each other because what law of non-contradiction states is implied in law of identity. But, we cannot by any means derive from ‘A is A” and ‘A is not A”. For example to say that sun will not rise tomorrow. The truth of a proposition dies imply the falsehood of its opposite, but to bring out this implication we need another statement which is independent. Hegel’s criticism of the law of non contradiction we need another statement is metaphysical and not logical. Since the prepositions of logic are independent of space and time they are formal in nature, they cannot be regarded to behave in the same manner as facts. Warm water may feel both not and cold, because what we mean is that warm is cool in relation to hot and hot in relation to cold. This will require two propositions. Therefore a proposition of logic can not have contradictory or contrary predicates.

Law of sufficient reason
It has been pointed out by Leibniz that if there is no sufficient reason for a thing or statement to be what is and not to be different from it, then its actual existence cannot be real. Thus everything in the world has a sufficient reason of its existence. According to leibniz the law of sufficient reason is applicable both in the field of metaphysics as well as of logic. In metaphysics there should be some sufficient reason for each for the innumerable things found in the world. God is the cause of the world and each instance in the world has its sufficient cause. In logic every Judgment has some or the other basis, without which it cannot be logical. Thus different judgments have different basis. Even where there is change, it has a sufficient reason.

The law of sufficient reason is complimentary to the law of identity. According to the law of identity. According to the law of identity the date should remain unchanged. The law of sufficient reason, on he other hand, points out that a thing is as it is. The law of sufficient reason, points out that a thing can change only when there is a sufficient reason for the change. In the absence of such a sufficient reason no change is possible. In other words, other things being the same a thing remains as it is- As the law of sufficient reason is complimentary to the law of identity, some scholars do not lake it part from the taw of identity and consider it as a part of it.

Instruments of thinking
Thinking calls for the assistance of percepts, images, concepts, signs and formulate, of which it make abundant use. These are the essential instruments of thinking:

(1) PERCEPTS- Percepts are important factors in thinking, affording material to it. They also stimulate thinking. Suppose we have seen our friend-doing something. The perception well set us thinking in order to discover ways and means of preventing our friend from this bad act.
Many other percepts will assist in this thinking. We will, with the help of memory, try to recall the perceptions of the past behaviour of our friend in order to see the cause which may have set him on his wrong path of life, in the hope of discovering ways and means which may be acted to cure him.

(2) IMAGES – Image too, is a kind of symbol which includes the faint recollection of perceptions. Past experiences of an individual move around in his mind in the form of images. Images may be recalled through a conscious effort but they also flash on the mind involuntarily. Many experiments have indicated that images are not quite as essential to thinking as they were previously considered to be, The use of images in thinking depend in no small measure upon the method of thinking, which the individual employs some people use other symbols in they thinking instead of images. It is not essential that a singer must have auditory images in order to be good. Thinking in philosophy and political science makes better use of words than images. Similarly subjects like arithmetic make every infrequent use of images. Some times a person experiences difficulty in making the other person comprehend his thought just because they differ in their ways of thinking.

(3) CONCEPTS -Concepts are the abstract forms of past experiences. Humanity is the trait of the human species, found equally in all human beings. Concept is a general idea and, as the example makes clear, it is founded upon perception. The concept of humanity cannot be formed without the perception of human being, because humanity is the common element in the perception of human beings. An abstraction of humanity from human being is necessary in order to proceed from perception to concept. Concept, formed with the help of abstraction is mental. Reasoning cannot be done without concepts, which are both abstract and general.
These are the indispensable elements of thinking. Classification of objects is done on the basis of concepts, while it differentiates between individuals of the same class. Conceptual thinking takes less time because it facilitates the thinking of innumerable things by a few concepts. Thus one concept is the symbol of many objects. But all concepts are not equally extensive. For example, creature is more comprehensive than human beings which in its turn, is more comprehensive than Indians. Indians are included in human beings who are included in creatures.

(4) SYMBOLS – Concepts are made use of in thinking mainly with the help of symbols, which are the representatives of general thoughts. Whenever our thoughts turn to human beings,the human figure, which occupies our mind is a general figure, not that of any specific person. The image of a dog is a symbol of dogs in general. One or its numerical equivalents are symbols of a whistle may be the symbols of unity while two or 2 symbolises dualism. The
sound of a whistle may be the symbol of a policeman or a watchman. The noise of the fire engine is the symbol of fire. Thus the use of symbols in thinking saves time and energy.

Terms and their classification
According to Aristotle, all propositions affirm or deny something. That about which an affirmation or denial is made is the subject term and that which an asserted of the subject is predicated term. The subject and the predicate are connected with each other by a copula, which always is some part of the verb “to be”. Let us now consider each element:

(1) Subject
– Consider the proposition “Man is moral”. Here mortality is being affirmed about man and, therefore man is the subject of his proposition. The subject may be one word or many. In the above example to has one word only; but in the proposition ‘Alexander” the I great, was pupil of Aristotle’, the subject is made of three words.

(2) Predicate - In the proposition ‘Man is mortal’, mortality is asserted about man and man is the subject therefore, mortal is the predicate Again, the predicate term may consist of single word, as in the above example, or it may have many words. In our second example “pupil of Aristotle” is the predicate an it consists of three words.

(3)Copula – The verb “is” and its conjugated serve as connect in words between subject and predicate, and this connecting word is called copula of the proposition. The word copula is derived from the copule, which means to join.

Words and Terms
All terms are words but every word cannot become a term in a proposition, From the viewpoint of logic, the words are divided into three categories, namely, Categorematic, Syncategorematic and Acategorematic. -”The categorematic words are those which by themselves can become the terms of a proposition.

1. The example of categorematic words are Ram, Peter, intelligent etc.
2. The syncategorematic words cannot by themselves terms but they become terms in conjuction with other words. For instance ‘and’ alone cannot be a
term but in “Ram and Peter are friends”, ‘and’ has become a term.
3. The acategorematic words like Ah and’bh can never be terms.

(1 ) Simple or Composite terms ” The simple terms consist of a single word only whereas the composite terms consist of two or more words, ‘man’, ‘boy’ ‘hence’ ‘intellectuals’ etc. are illustrations of single terms, and ‘an honest man’, ‘a swift horse’, ‘a good boy’ etc. are illustrations of composite terms.

(2) Singular or General Terms – A term which denotes or stands for a single individual or object is^ singular term whereas a term denoting a class is a general term. For example ‘Mount Everest’ ‘Ram’ ‘Delhi’ etc are cases of the former ‘Philosopher’ Book ‘mountain’ etc.are examples of the latter. Singular terms have been divided into two categories:

(a) Significant Singular Terms – Such a term not only stands for a single thing but mentions a trait peculiar to it not be found to in any other thing. For example, ‘Higher pack of the world’. ‘longest river’, ‘best cricketer of century’ each stand for one thing only and its peculair trait is unique to it.

(b) Proper names – These are known as non-significant singular terms also. Ram, Calcutta, London, Alfread Kinsey etc. Stand for any thing but do not name traits peculiar to them.

(3) Collective or Non collective Terms – ‘Arm/, ‘liberty’, ‘Crowd’ ‘audience’, ‘club’ etc, are terms which refer to collection of things. Army refers to a large collection of soldiers and officers, audience refers to a group of persons gathered to listen to something, club refers to group having some common purpose. However a club member or a soldier are obviously non collective terms.

(4) Concrete or Abstract Terms – The concrete terms are names of things such as books, balls etc. Whereas abstract terms are names of qualities. Sometime qualities and things are combined together, for example in literary book, magic balls etc. Abstract terms may be singular to general.

(5) Positive, Negative or Privative Terms – Positive terms indicate the presence of a quality such as ‘joy’, sorrow”, etc. While negative terms indicate absence of quality, e.g., ‘unmanly, immoral’ etc. privative terms are similar to negative in so far as they indicate absence of a quality but this absence of a quality is not natural. For example if we say man is blind, the term blind shows that be lacks eye sight but also shows that man ordinarily is not blind, therefore ‘blind’ indicate privation or deprivation of some trait.

A term can be understood either by considering the class of objects (a class may have one member) to which it applies by the set of characteristics which uniquely determine.
For example, the term ‘man’ be understood by pointing out to Ram, Shyam etc. who are men or may be understood to mean that any one who is a rational animal is a man. The class of objects to which a term applies is known as the denotation of the term and the set of characteristics which determine it is known as connotation of the term.

Denotation of a term is also known by another name, that is extension. As is clear from the word extension, denotation or extension of a term refers to extent or limit covered by a term. For instance the term ‘man’ applies to all members of mankind but the term ‘animal’ applies to members of mankind and besides also to members of animal kingdom. Therefore the term ‘animal’ has wider extension or application that the term ‘man’, while the term ‘Scholar* has even less extension than man.

It is also known as by another name intension. By connotation or intension we mean the idea or characteristics which enable anyone to apply a particular term to some object. For instance we say that this is a book because by book we understand a printed material covering some subject, and whatever answers to this description is also called book; therefore the intension or connotation of a term is equivalent to its description. However not everybody has the same description or set properties in mind with regard to a particular object. This is why we distinguish between various meanings of the term intension, or connotation. There are three such kinds:

1. Subjective Intension, 2. Objective Intension and 3. Conventional Intension.

The term ‘thief may suggest to someone’s minds a person who breaks into houses at night while some other person may understand by it anyone who steps else’s propserty. Obviously various people will have different ideas about the same thing depending upon their mental and emotional framework. The meaning which is peculiar to everybody is called subjective Intension of the term. Secondly, by cof<notation or intension we may intend or mean the properties belonging to a thing. This is known as Objective Intension or Comprehension. Thirdly, by connotation we can mean the essential properties of a thing which distinguish it from other and this is Conventional intension. This is roughly equivalent to definition of a term and ordinarily we have this meaning in when we use the term connotation.

Relation between Denotation and Connotation
It is usually believed that inverse relationship holds between connotation and denotation so that increase in one leads to decrease in the other. This relation is known as inverse relation between connotation and denotation. This relation operates in the following four ways;

1. An increase in the denotation results in decrease in the connotation. The term ‘rational animal’ applies to all men. but the term ‘animal’ applies to men
as well as dogs, cats etc. and had, therefore wider denotation. But as we see, its connotation is less than that of, ‘rational animal’ because rational animal must have both rationality and animality while animality alone is sufficient for the term ‘animals’.

2. A decrease in denotation leads to increase in connotation but as we know, scholar is a man who studies widely. Accordingly, the term ‘scholar’ has
greater connotation-

3. An increase in connotation results in decrease in denotation if we specify the kind of scholar and say a scholar of British constitution the term will apply to fewer persons than the term scholar, but obviously a British History scholar has more connotation.

4. Connotation results in decrease in denotation-

The term British Citizen has less connotation than the term citizen because the term citizen has the property of “being resident of a country”, whereas British citizen has another property in addition to above, namely “being British”. Therefore, the connotation of former is more than that of the latter, but, obviously the denotation of the latter is more.

The Rules Governing Inverse Relation Between Connotation and Denotation
1. Change in Connotation or Denotation results in a New Term-
Any change in a term either by specifying it further or by the removing some specifying gives us a new term. For example, if we add the quality of honesty and hard work to man, we get honest hard working man, and this is a new term. Therefore, by changing connotation of a man; we get a new term. Similarly, if we remove ‘honest or ‘hardworking’ from honest hardworking man, we get either honest man or hardworking man and this is a
new term.

2- The rule of inverse relation applies only if there is change in the term- If we add to the term man ‘biped’, ‘relation’, etc. There is no change, in the term.
because the term ‘man’, ‘biped man’, ‘rational man’ are same and there is no change in the connotation or denotation of the term man.

3. The inverse relation does not operate in mathematical proportion.
The extent to which change in qualities of a term results may be very small or very great, there is no question of proportion here. For instance, if we add ‘learned’ to the term ‘philosopher’ the change in the extent of ‘learned philosopher* and “philosopher”, is nominal, but if we add “first” to the above term, the new term can apply only to a single philosopher.

4. Change in Connotation or Denotation may not increase our knowledge- It is not necessary that if we learn some more characteristics of a thing, our
knowledge increases. For example, by saying that a play field is a hockey play .field, we do not know more.

What is syllogism?

Two type of inferences have been distinguished: the immediate and the mediate. While the immediate inference is based on one proposition only, the mediate has two propositions as its basis. The mediate inference is also known as syllogism, the name is due to Aristotle

A syllogism is defined as an arguement having three propostions, which contain between them three and only three terms, The two of these are premises and third is the conclusion. As a matter of fact, syllogism is a relation of two terms to a third term which helps discovery of some relation between the two. An example would make this clear; kissing in public is tolerated in permissive societies; USA is premissive society; therefore kissing in public is permitted in USA. Here “kissing’ and ‘USA’ have some relation with ‘permissive society* and in the conclusion we find kissing and USA related because of this common relation. Since it is through some common term that we reach the conclusion, syllogism, therefore, is a mediate inference.

Analysis of syllogism
A syllogism, as defined above, has^three propositions and three terms only. Two of the propositions are premises (one major and one minor) and the third one is the conclusion. Of terms, the premise counting the major term is the major premise. The premise containing minor term similarly is the minor premise. The term which occurs in both the premises is middle term. The determination of major and minor terms can easily be done by looking at the  conclusion, because the predicate of conclusion is the major term and the subject of the conclusion, minor. It is, therefore, not necessary that the premises occurring first must be the major premise, for instance, “The cinema is demoralising: and whatever is demortalising must be shunned”, therefore, cinema must be shunned”. In this argument minor premise comes first. In syllogism, like any deductive argument minor premise comes first. In syllogism, like any deductive argument, the conclusion must not exceed in extent to the extent of premises, and the truth of the conclusion depends upon both the premises being true.

Kinds of syllogism
The syllogism are broadly of two types, pure and mixed. In turn each has three sub-divisions;
Pure syllogism : Pure Categorical; Pure Hypothetical and Pure Disjunctive syllogism.
Mixed syllogisms : Hypothetical Categorical; Disjunctive Categorical and Dilemma

Rules of validity of syllogism
Logicians have been able to discover certain rules necessary for the validity of syllogism. These are as follows:

1. Three terms – A syllogism must have three and only three terms no less no more. If there two terms only inference can be immediate and not mediate. If there are four, the fallacy or four terms occurs. An argument like Ram is my friend. Mohan is Ram’s friend, therefore Mohan is my friend, is invalid because it has four terms, viz, Ram, Mohan my friend and Mohan’s friend. Secondly, there should be no ambiguous use of terms that is the meaning of a term should not change within the argument Violation of this rule leads to three kinds of fallacies;

(A) Ambiguous minor
Vice is to be condemned,
Ram is working with vice.
Ram is to be condemned.
‘Vice’ in minor means a tool and not evil as in the major.

(B) Ambiguous middle
Blue is a colour. -
Sky is blue.
Sky is a colour.

This is apparently false because white it is given that no Indians are ungrateful, this does not guarantee that no non-Indians are ungrateful, but the class of religious persons includes Indians as well as non- Indians.

4. If both the premises are negative, no conclusion follows-In case both premises are denials of certain attributes to subject terms, no connexion is established between major and minor terms through middle term. For example of one says A is not B and B is not C, we can not know whether A is C or is not C, because if, for example, Ram and Shyam are stupid . from this we cannot infer anything other than what is already asserted in propositions.

5. If one premise is negative, the conclusion is negative- In case one premise is negative, the other will be affirmative (this is entailed by Rule 5). Therefore the affirmative major minor will include or will be included by the middle, and the negative major or minor will exclude or be excluded by the middle, hence, conclusion will be negative. For example, if A is B and A is not C, the obvious conclusion is that A is not C.

6. From both affirmative premises, the conclusion will be affirmative- This is too obvious to need any explanation.

7. Two particular premises yield no conclusion-Two particular premises can either be II, 01 or 00. 00 is excluded by rule. 5, since both are negative. II is excluded by the Rule 3, because I proposition does not distribute either of its terms. In 10 or 01, the conclusion will be negative by Rule 6, and this negative conclusion will distribute the predicate, which is the major term. This will leave middle term undistributed.

8. If one of the premises is particular, the conclusion will also distributed therefore no term can be distributed in conclusion, because the number of distributed term had to be one less, hence conclusion must be particular. And if particular premise is negative, the conclusion will be negative. Now negative universal conclusion will distribute both the terms, and this will be equal to the number of distributed terms in the premises, because one premise is negative, the other has to be affirmative. Affirmative distributes one term only, and negative particular also distributes one term only. Now if conclusion is
negative universal both major and minor terms must be distributed and this will give rise to the fallacy of undistributed middle,

9- If the major premise is particular and the minor negative no conclusion follows-since the conclusion will be negative by Rule 5, and the predicate will be distributed major terms must terms must be distributed, but this will not be so if the major premise is I type.

The value of syllogism
Though Mill has criticized syllogism for being acircular argument its value cannot be  denied. It is of course true that all valid conclusion, are strictly implied in the premises, but to make explicit what is implicit requires intelligent procedure and is not automatic. For example, the syllogistic arguement: opium is poison and opium kills pain and therefore certain posions kill pain is not so simple as it may seem. As a matter of fact, medical science justifies use of so many poisonous substances by virtue of the reasoning of above type. Moreover, Knowledge is a matter of degree. An obvious truth for a physicist will be revelation for the lay man. Whenever we wish to know why x follow b, we-will have to argue syllogistically. Besides, as have seen, any set of three propositions is not a syllogism. Definite rules have to be observed. This helps us to know what to generalize and what not to generalize.

Science uses both deduction and induction. In deduction we learn about particular cases on the basis of certain genera! principles. Also called laws. However, the main business of any science is to establish these general principles or laws; with out these no science is possible. The general principles of science are derived by the rules of inductive reasoning. In order to derive a general principle, usually numerous instances are required, but this is not necessary, a single instance may suffice for this purpose. This process of arriving at general principles on the basis of a set of facts is known as generalization.

Definition of induction
According to Joyce, “Induction is the legitimate derivation  of universal laws from individual cases” And, according to Fowler, “Induction is the legitimate inference of general from particular or of the more general from the less general”,

From the above definitions it is clear that induction is a process of arriving at the general from the particulars. But the crucial question is what are the circumstances under which this transition can take place. In this connection, Mill had correctly warranted generalization where as in certain cases a single instance may suffice. Any one who knows more than this and knows when to generalize and when not to knows more than all ancient logicians and has solved the mystery of induction. However, the validity of induction is dependent upon two fundamental laws; the law of uniformity of Nature and the law of causation.

Charactrist1cs of scientific induction
Believing in the uniformity of Nature and the taw of causation a scientist generalizes.
Following are the characteristics of scientific Induction:

1.Establishment of Existential General propositions – This is the chief characteristics of induction. A proposition asserts something of something; it is particular when derived from experience. We can know only limited facts about an entire class and therefore, it asserts more than what is strictly experienced. But all induction is a leap from known to unknown on the basis of two above mentioned laws. Accordingly we establish proposition which we claim to hold for all known and unknown instance. Therefore by induction we establish general propositions.

2. Based  on Observed Facts – The second characteristic of induction is that it is basedon observed and experimental facts. For example, we know by observation and experiment that water boils at 100° centigrade at the sea level From this we induce a general proposition that “Water boils at 100  at the sea level”. Now this fact is not se of evident but an observed ‘act experimentally verified; and a general proposition derived on its basis is a verifiable proposition.

3.Inductive Leap-Mill calls induction a process of ‘transition from known to the unknown And Bain has called it a leap. “Induction is a leap to the future which has not yet come within observation began, to the remote where there has been no access to observe”. Very obviously inducation is a movement from known to the unobserved, and without this jump no generalization is  feasible. However, our jump is not irrational or arbitary. It is based on laws
of uniformity of Nature and causion.

Stages of inductive process
(a) Controlled observation under changing circumstances and Analysis of facts and elimination of Accidental- controlled observation is the first step in induction. By controlled observation v.e mean an organized experimental perception of certain facts, under changing circumstances, undertaken with a purpose in view. The facts discovered thus are next recorded systematically; memory is not to be relied upon.

The facts are now analyzed to find out which of them are essential to a phenomenon and which are accidental, I.e., without which a phenomenon would persist and not disappear. For example, the sweetness is essential for sugar; without sweetness there is no sugar. But without whiteness sugar does remain sugar but without sweetness it cannot be sugar. According to Mill those properties by removal of which a fact does not cease to be what it is
are accidental. The purpose of analysis is to eliminate the accidental.

(b) Formation of a Hypothesis-
While observing the facts a scientist has some hypothesis in mind regarding causal relations between these facts. For example a scientist observing unhealthy environment knows that unhealthy environment is causative of certain diseases. But only if a scientist has some tentative idea about the disease produced by a certain type of environment, would his observation be of any value. For example, excessive smoke in the air cause tuberculosis; but if a scientist finds somebody suffering from cancer in a smoky environment and he jumps to the conclusion that smoke causes cancer, he simply was not observing; because without hypothesis there can be no fruitful observation

(c) Generalization-
The next step of induction is generalization. On the basis of particular observed fact; a principle is derived. For example in a wide range of observation, we may find that the majority of Juvenile delinquents hail from broken homes, we can formulate the principle that broken home encourage criminality.

(d) Verification-
This means to testify the validity of a hypothesis. According to Flower verification is a novel method of providing hypothesis or sometimes it is used to test a deductive argument by means of an inductive argument and vice versa. If a hypothesis is verified it becomes a scientific principle,

Logicians have distinguished two modes of verification: Direct an Indirect. In direct verification actual observation and experiment is made. Indirect verification is in two stages. Firstly, we make a deduction from general statement and secondly, we verify the conclusion. For example, if we have a generalized premose that poverty induces can actually observe his.. behaviour. According to Jevous verification is the most crucial stage of induction without passing which induction is of little worth.

Relative importance of various stages induction
There is a controversy among logicians regarding the relative importance of different processes of induction. For instance, while Bacon regard analysis and elimination the most important elements in induction and hypothesis as minor element, when well regards generalization to be the most important element and virtually disregards the importance of hypothesis. Jevons regards generalization to be of very little importance and considers verification the most important feature of induction. From these contradictory opinions we see one thing, namely all elements and processes of induction are significant. According to their own conceptions various logicians have emphasized different aspects but none has considered any process totally irrelevant. There fore we may conclude that from analysis to verification we can not disregard any process. The difference of opinion is due to confusion between pure induction and scientific methods. The end of induction is generalization but the end of scientific method is verification. There is of course no inherent opposition between the two.

Kinds of induction
Induction is of two types: Improper and Proper Induction. The former has the form of an inductive argument but in fact, is not induction.
Improper Induction has three kinds: 1. Perfect Induction; 2. Induction by Parity of reasoning; and 3. Colligation of facts.
Proper Induction has also three kinds: 1. Scientific Induction; 2. Unscientific Induction or Induction per simple enumeration; and 3. Argument from Analogy.

The chart below illustrates it.
Improper Induction                                                                      Proper Induction
Perfect,By parity of reasoning,Collgation facts               Sceintific,Unscientific,Argument from analogy

(A) Perfect Induction – This is also called induction by total enumeration, that is, in it we examine each and every particular of a sample and then generalize. For example, if we verify the financial status of parents of student’s of a particular class of a school and discover that every student’s parents earn more than 1,000 rupees per month, we can easily conclude that the earnings of parents of these students in four figures. By this method we can easily say that no month of English Calendar is more than 31 days and less than 28 days or that books in the corner of library are all on Logic. Perfect induction is of course possible only where each particular is known. It is not possible here as we cannot possible know every member of a class. For example though we say that Indians are hospitable people or that Indians are religious, these are imperfect inductions because no one can verify the nature of each and every Indian nor his religious beliefs.

Perfect induction, however, is not true induction, it is merely a collection of facts.
Following argument are advanced against perfect induction.

1. No Inductive Leap: There is no real inference, no addition to knowledge. It is merely verbal.
2. Apparently General: It is merely a heap of singular facts, registered in short-hand. Instead of saying A, B. C, D are industrialists and rich, we say all
industrialists are rich. This is no more than verbal transformation.

(B) Induction by parties of Reasoning- This is a type of argument in which on the basis of similarity we generalized from a single example. For instance, from a single triangle we can call triangles are figures with three sides. This is of course true but that the difficulty is that such arguments are not based on observation or experiment.

(C) Colligation of facts – According to Mill, “Colligation is that mental observation which enables us bring as number of actual phenomenon under description, or which enables us to sum up a number of details in a single proposition”. Our conception of things is based on such Colligation. Having found sugar to be hard, white, sweet etc., we form a conception of sugar, viz.. sugar is a complex of these qualities or a substance in which these various
qualities inhere. However as Milt says, colligation of facts is not necessarily induction- It is not induction because something is deductive and involves no inference. Though Whewell who introduced this concept regarded it as Induction, it is considered improper induction by most logicians.

Kinds of proper induction
(A) Scientific- Modem Logicians consider it to be perfect, because scientific conclusions are based on causal relation, are not doubtful, whereas unscientific. induction is accidental and not based on any law or principle. However, induction on the basis of analogy is valid.

(B) Unscientific — As noted above, this is based on accidental properties. It is based upon simple enumeration.
(C) Analogical- This is based upon certain features between various things. For example, lemon and orange and tamarind are all sour. Therefore, they are
called citrus fruits.

Like wise deduction, induction also has two aspects: formal and material. As carveth Read has observed, observation and experiment are the material grounds of induction. The validity of induction is directly dependent upon the correctness of observation and soundness of experiment. Obviously, in the absence of careful observation and well-planned experiment our fates will be of doubtful validity and the induction no more than a conjecture, It is for this
reason that there is great emphasis on the properness of observation and experiment in very science. Every scientist is required to be objective and free from presuppositions or prejudices of any Kind.

Observation is careful and purposeful inspection of a situation and experiment is controlled observation in which facts are analyzed and controlled by the help of appratus etc. Iin order to determine cause-effect relationship between various facts. Induction is generalization and good observation and proper experiment are the foundation of generalization.

Law of elimination
According to Mill  the experimental methods are basically the methods of elimination.
Therefore, methods of elimination are the bases of experiment method. Below we make comparison of experimental methods and the procedure of elimination.

(1) Basis of the Method of agreement- In this, elimination helps in the following manner. Whatever antecedent can be left out without prejudice to the effect cannot be the part of cause. For example, a man suffering from cancer, but we want to know what caused death. We know he had a bad throat but we also know that bad throat never results in death and same is true of poor vision and deafness. Accordingly, we eliminate these antecedents and come to the conclusion that cancer caused death.

(2) Basis of the Method of Difference- When an antecedent cannot be left out without the consequent disappearing, some such antecedent must be cause or that part of the cause, according to Mill. This clearly shows that procedure of elimination is at the root of this method also. If a thing tied to one end of rope falls when the rope is cut in the middle, surely rope is the cause of holding that thing.

(3) Basis of the Method of Concomitant Variation- an antecedent and a consequent rising and falling together in numerical concomitance are to be held as cause and effect. For example, if a person always gets stomachache on eating oyster then oyster must be the cause of his pain.

(4) Basis of the method of Residues- According to Joseph “Nothing is the cause of a phenomenon, if it is known to be the cause of some other Phenomenon”. Failure for example, cannot be the cause of one’s happiness, as it is known to be the cause of depression and gloom.

Mill has defined the method of agreement in the following words; “if two or more instances of a phenomenon under investigation have only one circumstance in common, the circumstance in which all the instances agree is the cause (or effect) of the given phenomenon”. According to this method if we wish to know the cause or effect of something we should examine several instances similar to one under investigation, and if they are found to have one common factor, then this common factor is the cause of the effect upon whether it is antecedent or consequent of the phenomenon. Antecedent factor is always the cause and the consequent factor the effect. For example, if we wish to know the cause of malaria, we find that being bitten by a mosquito is the only factor present in all of them, then mosquito bite is be cause of malaria. Mellone and Coffee have termed this method as a method of exclusive agreement in as much as the various examples of a phenomenon agree In one and only one respect.

The method of arrangement is considered to be primarily a method for observation and not experiment, because the use of this method is made in those cases where the control of condition is not feasible and therefore no experiment is possible. The advantages of these methods are the same as the advantages of observations. The range of phenomenon in which this method can be applied is very wide and moreover, by the use of this method, we can move from cause to effect or effect or to the cause. That is we discover the cause of a given phenomenon or can discover the effect of a certain phenomenon.

Defects of the method of agreement
The method of agreement is not a foolproof procedure of discovering the cause of a phenomenon, nor is if a perfect method of proof or demonstration. Its chief defects are: -

(1) Difficulty of distinguishing cause and co-existences – The sky and the ocean co-exists because where ever there is ocean there is sky, but surely none of them is the cause of the other. Therefore confusion of cause and co-existences has to be avoided but this is not an easy thing,

(2) Plurality of causes – Men are killed by pistol shots, accordingly we may believe that pistol shot is the cause of death. But as we know, pistol shot is fired due to some reason. All inspectors shoot at criminals, a husband shoots his wife because she is found in the act of adultery. As can be seen. the cause of a person’s death may not be a single factor but plurality of factors.

(3) Antecedent and consequent not easily distinguishable- there are situations where is difficult to say what precedes and what follows. For example, in the famous James- Lange theory of emotion, it is not easy to say whether bodily changes are consequent upon emotion or emotion is the effect if bodily changes. Again, A stops seeing B and be friends C. Now A stopped seeing B due to either dissatisfaction with B or due to the better personality of

C. Such examples prove that antecedent and consequent is not always easy to distinguish.

(4) Possibility of non-observation – Milk becomes curd on being soured.
Accordingly we believe that milk curdles on account of addition of something sour. However, milk curdles in few hours during summer if left unboiled. Now the real cause of milk becoming curd is something which is not perceived because we cannot see bacteria, the real cause of curd.

Joint Method Of Agreement And Difference
According to Mill, “If two or more instance in which the phenomenon occurs have only one circumstance in common, while two to more instance in which it does not occur have nothing in common save the absence of that circumstances, the circumstances in which alone the two sets of instance differ is the effect, or the cause, or an indispensable part of the cause, of the phenomenon”. For example, we find, in summer dewdrops on things, which are good conductor of heat. Accordingly, we may well conclude that discharge of heat is the cause of dew. Again, as Flower says, if a certain food is not eaten, we may be doubly sure that the particular food is the cause of the pain. As in this method there is comparison between two sets of instances, this is also known as Method of Double Agreement. Mill has termed this method as Indirect Method of Difference.

Comparison with the Method of Agreement
The joint method is productive of more reliable results than the method of Agreement.
Reason for this is obvious. If upon eating radishes we get stomachache; we cannot be very sure that radishes are the cause of pain but if we regularly observe this happening and do not get pain upon not eating radishes, our belief will be more reliable.

Secondly, this method helps in removing the defect due to plurality of causes.

Mill has defined the method of difference thus: “If an instance in which the phenomenon under investigation occurs, and an instance in which it does not occur have every circumstance in common save one, than one occurring only in the former; the circumstance in which alone two instances differ is the effect, or the cause or an indispensable part of the cause two of the phenomenon”. And according to Meltone, “When the addition of an agent is followed by the appearance, or its substances by the disappearance, of a certain event, other circumstances remaining the same, the agent is causally connected with the event”.

The method of difference requires two instances, which resemble each other in every other respect, but differ in the presence or absence of the phenomenon investigated. Mill has recognized the limitations of the method of agreement because we cannot be certain that the phenomenon investigated has one cause only. He, however, thought that method of difference overcomes the defects of the first method. According to the rule of difference nothing can be the cause of a phenomenon if the phenomenon falls to occur when cause occurs. For example, if clouds are considered as the ’cause’ of rain, then every appearance of clouds in the sky should be followed by rain.

This does not happen many a time: therefore clouds cannot be considered to be the cause of rain. Few more example, will further clarify the point:

1.The bell rings if there is air in the room; but if there is vacuum in the room it does | not. Therefore air is the cause of ringing. ;
2. A man dies of snake bite but he was perfectly healthy before, therefore snakebite is the cause of death.
3. A cup of tea lasts bitter, but upon the addition of sugar bitterness disappears. Therefore, sugar is the cause of sweetness of tea.

Characteristics of the method of difference:
1. Cause may be partial – A man dies on hearing he had got first prize in lottery. Now this news alone may not be the cause, but only an accidental factor. The real cause may be weak heart.

2. A man does not sleep in the night he drinks coffee. A vegetable becomes pleasant tasting on addition of salt. In these two examples it will be wrong to believe that coffee is the only cause of sleeplessness and that addition of salt makes vegetables pleasant. This method would commit us to believe in these connections.

3. Post Hoc Ergo Propter Hoc – Sleeplessness may occur due to coffee or may not occur due to coffee, but to believe that upon taking coffee we would not sleep, therefore coffee causes sleeplessness is to commit the fallacy of believing that what follows is the effect of what precedes.

Requirement of the method of difference:
The above mentioned defects not withstanding the method of difference is a useful experimental method. However, its effective use requires fulfillment of following conditions:

1.Only a single factor should be varied at one time – For example if a person is if suffering from headache and he is given to eat chicken sandwiches, raw eggs and couple of aspirins and B complex tablets, and his headache goes it cannot be determined as to which of the things cured this headache.

2. Cause and occasion must be distinguished – If we open water tap, wafer starts flowing. Can we say that opening the tap is the cause of water flow? Obviously not, because the cause of water flow is the presence of water in the mains and opening the tap is only an occasion that removes resistance.

3.’ Time Factor – If we allow too much time to elapse between varying a circumstance and observing the effect, some other causes may intervene and mark the real cause. For, example, a man is given a drug, which kills him in six months. Now it will be hazardous to believe drug to be the cause of death because in six-month time many things could have happened to him.

Comparisons between difference method and agreement method:
The method of difference is peculiarly an experimental method and therefore more effective. Following are its advantages as compared with the Methods of agreement.

1. It is more effective than agreement method in establishing cause- effect relationship between two phenomena.
2. It is more suited to testing of hypothesis.
3. It is Jess liable to err in the cases where causes are plural.
4. If requires only two instances.
5. ft is more scientific and capable of experiment.

Method of Difference and Joint Method:
1. Whereas Joint Method requires at least four instances Difference Method needs only one.
2. Whereas Difference Method is experimental. Joint Method is suited to observation alone.
3. It is more difficult to fulfill requirements of Difference method but at the same time the conclusions arrived by it are far more reliable than those reached by the Joint Method.

The above points make it clear that in spite of superficial resemblance the two methods are very different-

The Method of Concomitant Variation
The elimination of unnecessary conditions, which formed the basis of Agreement and Difference methods, cannot be done in all cases. For example, if we are studying tides in rivers and seas. we cannot use the canon of difference, since we cannot find an instance in which such a body of water does not show the tidal behaviour. In such cases we may notice or introduce variations in some circumstance, without thereby completely eliminating either the effect or the cause. The method of concomitant variation has been formulated by Mill thus;

“Whatever phenomenon varies in any manner whenever another phenomenon varies in some particular manner is either a cause or an effect of that phenomenon; or is connected with it through some fact of causation”. Following elements are not worthy in this definition;

1. Correlation — This method is usable in those cases only in which increase or decrease in a phenomenon is corresponding to increase or decrease in other. In other words, change in the two has direct relation.

2. Inverse Change – This method is usable in those cases also in which increase or decrease in one phenomenon is matched by proportionate decrease or increase in the other phenomenon. Here the relationship in the phenomenon is inverse.

The nature of this method will be made clear by some examples:
1. Pascal’s Example – Pascal tried to determine the atmospheric pressure by observing variation in the height of mercury column in the barometer. He discovered that as we go to higher altitudes and atmospheric pressure decreases, the height of mercury column rises respectively.

2. Albert’s Example – By using this method Albert discovered a definite co relationship between waxing and warning of moon and tides in the rivers and seas. _

3. Example from Social Behaviour – Criminologists have found that as the means of communication become more and more sophisticated, the rate of Juvenile crime rises in a definite proportion; and as means of communication become more and more sparse the rate declines. We also find that incidence of the tax evasion is higher in countries with heavy taxation and is low in those countries where the rate is low.

4. Psychology – Psychologists have established definite correlation between frustration and violence.

Features of concomitant variation method:
1. Usable even where elimination is not possible – This method is applicable to situations where we cannot exclude certain factors and preserve the effect of their absence.

2. Qualification – This is the only method in which it is possible to quantify cause and effect. For example, we know by this method that a certain amount of drug is required for cure of a particular disease. Also we know that distortion of personality is proportionate to the amount of repression.

Defect -  Along with good points, this method suffers from the following defects :
1. Applicable only to Observed Facts – In as much as this method requires that the -effect-of variation of phenomenon should be perceivable in some other phenomenon, this is possible only where both are present and observable. We cannot for example establish concomitant variation relationship between present efforts of a men and the amount of salary he will get after taking the degree.
2. Inapplicable in Qualitative changes ~ If there is qualitative change from cause to effect this method is inapplicable.

Defining the method of residues, Mill said, “Substract from any given phenomenon such part as is known by previous inductions to be the effect of certain antecedents, and the residue of the phenomenon is the effect of the remaining antecedents”. The method of Residues is a modification of the Method of Difference. It is an important way of investigating nature. Inquiry into the sound left a residual city might arise from the heat developed in the fact of condensation, which takes place at every vibration by which sound is conveyed.

The important features of this method are:
1. A cause of one phenomenon cannot be the cause of the other.
2. It is a method of discovery. It is a finger post to unexplained.
3. This method uses deduction primarily.
4. It is a modification of difference Method,

Definition and Place of Deduction
Though the main business of science is discovery of facts, and, therefore, scientific investigation involves induction, no facts can be discovered without use of some hypothesis.
Besides, the business of science is not merely collection of data but the perception of significant relations and connections in facts. For these purpose the use of deduction is necessary. As a matter of fact deduction and induction are not opposed to each other, though descriptions general to particular and particular to general suggest so if they are mutually exclusive-they are twin processes of reasoning and each complements the other. To consider an example from decial science® A. B, C, D… bitten by mad dog develops hydrophobia (fear of water) and dies, therefore the saliva of mad dog is poisonous. Working on this basis doctors produce a vaccine to counter act this poison. Now whoever gets bitten by reasoning, as we may perceive is wholly deductive here; whoever is bitten by mad dog is given injection, A is bitten by mad dog, therefore A is to be given injections.

It should be remembered that deduction is used in investigation where induction is not usable. J For example, if we know that the bite of a mad dog is highly dangerous and results in sure death unless antidote injection is given and we comes across a man whom a mad dog has bitten. Now should we act upon our assumptions and send him to hospital or should we watch for the effect of bite upon the person in question? Obviously, we must act upon our assumption. Of course, if a man is bitten by a domestic dog, we shall wait to see if the dog goes mad and dies ultimately. In brief in the case of established principle we can and should think deductively and here we are studying facts to arrive at a conclusion we must observe facts carefully upon the basis of our hypothesis.

Kinds of Deduction
(1) Direct Deductive Method or the Physical Method.
(2 A Inverse Deduction Method or the Historical Method.
(3) Abstract Deductive Method or the Geometrical Method.

1. Direct Deduction or the Physical Method- As can be perceived by the name in  this method of physical facts, deductive derivation and verification are involved. Carveth Read has described this method very aptly in the following words, “Given any complex mechanical phenomenon, an inquirer considers (1) what laws that already ascertained by induction seem likely to apply to it (in default to known laws’,’ hypothesis are subtended); he can then (2) compute the effect that will follow from these laws, in circumstances similar the case before him and (3) he verifies his conclusion by comparing it with the actual phenomena”. Under the& method we first -try-to find out what are the rules, already established by induction, which are most likely to apply to a given phenomenon and having made selection with the help of deduction, deduce an instance and then verify it by observation or experiment. For example if a doctor finds that a particular patient has bleeding teeth, and from his experience’ concludes that this is a case of acute deficiency of vitamin C he will make some more fests based upon the general rule of vitamin C, deficiency. For example he will notice his skin and scratch it a little, if this leads to oozing of blood he will be confirmed in his diagnosis

2. Inverse or Historical Deduction – the first step -of this method is induction. By observation we try to establish the cause or causes of complex situation. For example, by historical observation we can come to know the cause of Jharkhand movement. Geographical heterogeneity, Cultural differences, exploitation etc. are some causes. Now we establish by deductive reasoning the real cause. We find that whenever there are cultural differences or geographical disparity, the popular discontent does not follow. There fore we carry our study deeper and find that exploitation, particularly economic, is the root cause of trouble. Now this arrived by deductive reasoning.

3. Geometrical method – This is purely deductive method and it is unconnected with any inductive processes because it is not based on observation or experiment. Its terms are abstract and not concrete. This method is used in used in mathematics and formal logic


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