This ultimate fact of our nature, this natural inbred constitutional impatience, explains more than half of the wrong beliefs that we form and persist in. We must have a belief of some kind: we cannot be happy till we get it, and we take up with the first that seems to show the way clear. It may be right or it may be wrong: it is not, of course, necessarily always wrong: but that, so far as we are concerned, is a matter of accident. The pressing need for a belief of some sort, upon which our energies may proceed in anticipation at least, will not allow us to stop and inquire. Any course that offers a relief from doubt and hesitation, any conviction that lets the will go free, is eagerly embraced.

It may be thought that this can apply only to beliefs concerning the consequences of our own personal actions, affairs in which we individually play a part. It is from them, no doubt, that our nature takes this set: but the habit once formed is extended to all sorts of matters in which we have no personal interest. Tell an ordinary Englishman, it has been wittily said, that it is a question whether the planets are inhabited, and he feels bound at once to have a confident opinion on the point. The strength of the conviction bears no proportion to the amount of reason spent in reaching it, unless it may be said that as a general rule the less a belief is reasoned the more confidently it is held.

"A grocer," writes Mr. Bagehot in an acute essay on "The Emotion of Conviction,"[2] "has a full creed as to foreign policy, a young lady a complete theory of the Sacraments, as to which neither has any doubt.

A girl in a country parsonage will be sure that Paris never can be taken, or that Bismarck is a wretch." An attitude of philosophic doubt, of suspended judgment, is repugnant to the natural man. Belief is an independent joy to him.

This bias works in all men. While there is life, there is pressure from within on belief, tending to push reason aside. The force of the pressure, of course, varies with individual temperament, age, and other circumstances. The young are more credulous than the old, as having greater energy: they are apt, as Bacon puts it, to be "carried away by the sanguine element in their temperament". Shakespeare's Laertes is a study of the impulsive temperament, boldly contrasted with Hamlet, who has more discourse of reason. When Laertes hears that his father has been killed, he hurries home, collects a body of armed sympathisers, bursts into the presence of the king, and threatens with his vengeance--the wrong man. He never pauses to make inquiry: like Hotspur he is "a wasp-stung and impatient fool"; he must wreak his revenge on somebody, and at once. Hamlet's father also has been murdered, but his reason must be satisfied before he proceeds to his revenge, and when doubtful proof is offered, he waits for proof more relative.

Bacon's _Idola Tribus_ and Dr. Bain's illustrations of incontinent energy, are mostly examples of unreasoning intellectual activity, hurried generalisations, unsound and superficial analogies, rash hypotheses. Bacon quotes the case of the sceptic in the temple of Poseidon, who, when shown the offerings of those who had made vows in danger and been delivered, and asked whether he did not now acknowledge the power of the god, replied: "But where are they who made vows and yet perished?" This man answered rightly, says Bacon.

In dreams, omens, retributions, and such like, we are apt to remember when they come true and to forget the cases when they fail. If we have seen but one man of a nation, we are apt to conclude that all his countrymen are like him; we cannot suspend our judgment till we have seen more. Confident belief, as Dr. Bain remarks, is the primitive attitude of the human mind: it is only by slow degrees that this is corrected by experience. The old adage, "Experience teaches fools,"

has a meaning of its own, but in one sense it is the reverse of the truth. The mark of a fool is that he is not taught by experience, and we are all more or less intractable pupils, till our energies begin to fail.

_The Bias of Happy Exercise._

If an occupation is pleasant in itself, if it fully satisfies our inner craving for action, we are liable to be blinded thereby to its consequences. Happy exercise is the fool's Paradise. The fallacy lies not in being content with what provides a field for the full activity of our powers: to be content in such a case may be the height of wisdom: but the fallacy lies in claiming for our occupation results, benefits, utilities that do not really attend upon it. Thus we see subjects of study, originally taken up for some purpose, practical, artistic, or religious, pursued into elaborate detail far beyond their original purpose, and the highest value, intellectual, spiritual, moral, claimed for them by their votaries, when in truth they merely serve to consume so much vacant energy, and may be a sheer waste of time that ought to be otherwise employed.

But as I am in danger of myself furnishing an illustration of this bias--it is nowhere more prevalent than in philosophy--I will pass to our next head.

_The Bias of the Feelings._

This source of illusion is much more generally understood. The blinding and perverting influence of passion on reason has been a favourite theme with moralists ever since man began to moralise, and is acknowledged in many a popular proverb. "Love is blind;" "The wish is father to the thought;" "Some people's geese are all swans;" and so forth.

We need not dwell upon the illustration of it. Fear and Sloth magnify dangers and difficulties; Affection can see no imperfection in its object: in the eyes of Jealousy a rival is a wretch. From the nature of the case we are much more apt to see examples in others than in ourselves. If the strength of this bias were properly understood by everybody, the mistake would not so often be committed of suspecting bad faith, conscious hypocrisy, when people are found practising the grossest inconsistencies, and shutting their eyes apparently in deliberate wilfulness to facts held under their very noses. Men are inclined to ascribe this human weakness to women. Reasoning from feeling is said to be feminine logic. But it is a human weakness.

To take one very powerful feeling, the feeling of self-love or self-interest--this operates in much more subtle ways than most people imagine, in ways so subtle that the self-deceiver, however honest, would fail to be conscious of the influence if it were pointed out to him. When the slothful man saith, There is a lion in the path, we can all detect the bias to his belief, and so we can when the slothful student says that he will work hard to-morrow, or next week, or next month; or when the disappointed man shows an exaggerated sense of the advantages of a successful rival or of his own disadvantages. But self-interest works to bias belief in much less palpable ways than those. It is this bias that accounts for the difficulty that men of antagonistic interests have in seeing the arguments or believing in the honesty of their opponents. You shall find conferences held between capitalists and workmen in which the two sides, both represented by men incapable of consciously dishonest action, fail altogether to see the force of each other's arguments, and are mutually astonished each at the other's blindness.

_The Bias of Custom._

That custom, habits of thought and practice, affect belief, is also generally acknowledged, though the strength and wide reach of the bias is seldom realised. Very simple cases of unreasoning prejudice were adduced by Locke, who was the first to suggest a general explanation of them in the "Association of Ideas" (_Human Understanding_, bk. ii.

ch. xxxiii.). There is, for instance, the fear that overcomes many people when alone in the dark. In vain reason tells them that there is no real danger; they have a certain tremor of apprehension that they cannot get rid of, because darkness is inseparably connected in their minds with images of horror. Similarly we contract unreasonable dislikes to places where painful things have happened to us. Equally unreasoning, if not unreasonable, is our attachment to customary doctrines or practices, and our invincible antipathy to those who do not observe them.

Words are very common vehicles for the currency of this kind of prejudice, good or bad meanings being attached to them by custom. The power of words in this way is recognised in the proverb: "Give a dog a bad name, and then hang him". These verbal prejudices are Bacon's _Idola Fori_, illusions of conversation. Each of us is brought up in a certain sect or party, and accustomed to respect or dishonour certain sectarian or party names, Whig, Tory, Radical, Socialist, Evolutionist, Broad, Low, or High Church. We may meet a man without knowing under what label he walks and be charmed with his company: meet him again when his name is known, and all is changed.

Such errors are called Fallacies of Association to point to the psychological explanation. This is that by force of association certain ideas are brought into the mind, and that once they are there, we cannot help giving them objective reality. For example, a doctor comes to examine a patient, and finds certain symptoms. He has lately seen or heard of many cases of influenza, we shall say; influenza is running in his head. The idea once suggested has all the advantage of possession.

But why is it that a man cannot get rid of an idea? Why does it force itself upon him as a belief? Association, custom, explains how it got there, but not why it persists in staying.

To explain this we must call in our first fallacious principle, the Impatience of Doubt or Delay, the imperative inward need for a belief of some sort.

And this leads to another remark, that though for convenience of exposition, we separate these various influences, they are not separated in practice. They may and often do act all together, the Inner Sophist concentrating his forces.

Finally, it may be asked whether, seeing that illusions are the offspring of such highly respectable qualities as excess of energy, excess of feeling, excess of docility, it is a good thing for man to be disillusioned. The rose-colour that lies over the world for youth is projected from the abundant energy and feeling within: disillusion comes with failing energies, when hope is "unwilling to be fed". Is it good then to be disillusioned? The foregoing exposition would be egregiously wrong if the majority of mankind did not resent the intrusion of Reason and its organising lieutenant Logic. But really there is no danger that this intrusion succeeds to the extent of paralysing action and destroying feeling, and uprooting custom.

The utmost that Logic can do is to modify the excess of these good qualities by setting forth the conditions of rational belief. The student who masters those conditions will soon see the practical wisdom of applying his knowledge only in cases where the grounds of rational belief are within his reach. To apply it to the consequences of every action would be to yield to that bias of incontinent activity which is, perhaps, our most fruitful source of error.

[Footnote 1: Bain's _Logic_, bk. vi. chap. iii. Bacon intended his _Idola_ to bear the same relation to his _Novum Organum_ that Aristotle's Fallacies or Sophistical Tricks bore to the old Organum. But in truth, as I have already indicated, what Bacon classifies is our inbred tendencies to form _idola_ or false images, and it is these same tendencies that make us liable to the fallacies named by Aristotle. Some of Aristotle's, as we shall see, are fallacies of Induction.]

[Footnote 2: Bagehot's _Literary Studies_, ii. 427.]

III.--THE AXIOMS OF DIALECTIC AND OF SYLLOGISM.

There are certain principles known as the Laws of Thought or the Maxims of Consistency. They are variously expressed, variously demonstrated, and variously interpreted, but in one form or another they are often said to be the foundation of all Logic. It is even said that all the doctrines of Deductive or Syllogistic Logic may be educed from them. Let us take the most abstract expression of them, and see how they originated. Three laws are commonly given, named respectively the Law of Identity, the Law of Contradiction and the Law of Excluded Middle.

1. _The Law of Identity._ A is A. Socrates is Socrates. Guilt is guilt.

2. _The Law of Contradiction._ A is not not-A. Socrates is not other than Socrates. Guilt is not other than guilt. Or A is not at once _b_ and not-_b_. Socrates is not at once good and not-good. Guilt is not at once punishable and not-punishable.

3. _The Law of Excluded Middle._ Everything is either A or not-A; or, A is either _b_ or not-_b_. A given thing is either Socrates or not-Socrates, either guilty or not-guilty. It must be one or the other: no middle is possible.

Why lay down principles so obvious, in some interpretations, and so manifestly sophistical in others? The bare forms of modern Logic have been reached by a process of attenuation from a passage in Aristotle's _Metaphysics_[1] (iii. 3, 4, 1005_b_ - 1008). He is there laying down the first principle of demonstration, which he takes to be that "it is impossible that the same predicate can both belong, and not belong, to the same subject, at the same time, and in the same sense".[2]

That Socrates knows grammar, and does not know grammar--these two propositions cannot both be true at the same time, and in the same sense. Two contraries cannot exist together in the same subject. The double answer Yes and No cannot be given to one and the same question understood in the same sense.

But why did Aristotle consider it necessary to lay down a principle so obvious? Simply because among the subtle dialecticians who preceded him the principle had been challenged. The Platonic dialogue Euthydemus shows the farcical lengths to which such quibbling was carried. The two brothers vanquish all opponents, but it is by claiming that the answer No does not preclude the answer Yes. "Is not the honourable honourable, and the base base?" asks Socrates. "That is as I please," replies Dionysodorus. Socrates concludes that there is no arguing with such men: they repudiate the first principles of dialectic.

There were, however, more respectable practitioners who canvassed on more plausible grounds any form into which ultimate doctrines about contraries and contradictions, truth and falsehood, could be put, and therefore Aristotle considered it necessary to put forth and defend at elaborate length a statement of a first principle of demonstration.

"Contradictions cannot both be true of the same subject at the same time and in the same sense." This is the original form of the Law of Contradiction.

The words "of the same subject," "at the same time," and "in the same sense," are carefully chosen to guard against possible quibbles.

"_Socrates knows grammar._" By Socrates we must mean the same individual man. And even of the same man the assertion may be true at one time and not at another. There was a time when Socrates did not know grammar, though he knows it now. And the assertion may be true in one sense and not in another. It may be true that Socrates knows grammar, yet not that he knows everything that is to be known about grammar, or that he knows as much as Aristarchus.

Aristotle acknowledges that this first principle cannot itself be demonstrated, that is, deduced from any other. If it is denied, you can only reduce the denier to an absurdity. And in showing how to proceed in so doing, he says you must begin by coming to an agreement about the words used, that they signify the same for one and the other disputant.[3] No dialectic is possible without this understanding.

This first principle of Dialectic is the original of the Law of Identity. While any question as to the truth or falsehood of a question is pending, from the beginning to the end of any logical process, the words must continue to be accepted in the same sense.

Words must have an identical reference to things.

Incidentally in discussing the Axiom of Contradiction ([Greek: axioma tes antiphaseos]),[4] Aristotle lays down what is now known as the Law of Excluded Middle. Of two contradictories one or other must be true: we must either affirm or deny any one thing of any other: no mean or middle is possible.

In their origin, then, these so-called Laws of Thought were simply the first principles of Dialectic and Demonstration. Consecutive argument, coherent ratiocination, is impossible unless they are taken for granted.

If we divorce or abstract them from their original application, and consider them merely as laws of thinking or of being, any abstract expression, or illustration, or designation of them may easily be pushed into antagonism with other plain truths or first principles equally rudimentary. Without entering into the perplexing and voluminous discussion to which these laws have been subjected by logicians within the last hundred years, a little casuistry is necessary to enable the student to understand within what limits they hold good.

_Socrates is Socrates._ The name Socrates is a name for something to which you and I refer when we use the name. Unless we have the same reference, we cannot hold any argument about the thing, or make any communication one to another about it.

But if we take _Socrates is Socrates_ to mean that, "An object of thought or thing is identical with itself," "An object of thought or thing cannot be other than itself," and call this a law of thought, we are met at once by a difficulty. Thought, properly speaking, does not begin till we pass beyond the identity of an object with itself.

Thought begins only when we recognise the likeness between one object and others. To keep within the self-identity of the object is to suspend thought. "Socrates was a native of Attica," "Socrates was a wise man," "Socrates was put to death as a troubler of the commonweal"--whenever we begin to think or say anything about Socrates, to ascribe any attributes to him, we pass out of his self-identity into his relations of likeness with other men, into what he has in common with other men.

Hegelians express this plain truth with paradoxical point when they say: "Of any definite existence or thought, therefore, it may be said with quite as much truth that it _is not_, as that it _is_, its own bare self".[5] Or, "A thing must other itself in order to be itself".

Controversialists treat this as a subversion of the laws of Identity and Contradiction. But it is only Hegel's fun--his paradoxical way of putting the plain truth that any object has more in common with other objects than it has peculiar to itself. Till we enter into those aspects of agreement with other objects, we cannot truly be said to think at all. If we say merely that a thing is itself, we may as well say nothing about it. To lay down this is not to subvert the Law of Identity, but to keep it from being pushed to the extreme of appearing to deny the Law of Likeness, which is the foundation of all the characters, attributes, or qualities of things in our thoughts.

That self-same objects are like other self-same objects, is an assumption distinct from the Law of Identity, and any interpretation of it that excludes this assumption is to be repudiated. But does not the law of Identity as well as the law of the likeness of mutually exclusive identities presuppose that there are objects self-same, like others, and different from others? Certainly: this is one of the presuppositions of Logic.[6] We assume that the world of which we talk and reason is separated into such objects in our thoughts. We assume that such words as _Socrates_ represent individual objects with a self-same being or substance; that such words as _wisdom_, _humour_, _ugliness_, _running_, _sitting_, _here_, _there_, represent attributes, qualities, characters or predicates of individuals; that such words as _man_ represent groups or classes of individuals.

Some logicians in expressing the Law of Identity have their eye specially upon the objects signified by general names or abstract names, _man_, _education_.[7] "A concept is identical with the sum of its characters," or, "Classes are identical with the sum of the individuals composing them". The assumptions thus expressed in technical language which will hereafter be explained are undoubtedly assumptions that Logic makes: but since they are statements of the internal constitution of some of the identities that words represent, to call them the Law of Identity is to depart confusingly from traditional usage.[8]

That throughout any logical process a word must signify the same object, is one proposition: that the object signified by a general name is identical with the sum of the individuals to each of whom it is applicable, or with the sum of the characters that they bear in common, is another proposition. Logic assumes both: Aristotle assumed both: but it is the first that is historically the original of all expressions of the Law of Identity in modern text-books.