tion. 2. A Judgment is a combination of two concepts, related to one or more Common objects of possible intuition. 3. A Syllogism is a combination of two judgments, necessitating a third judgment as the consequence of their mutual relation." (Mansel, Prolegomena Logica, pp. 62-9, ed. 1860.)

181. "The mental powers employed in the acquisition of knowledge are probably three in number. They are substantially as Professor Bain has stated them (Senses and Intellect, 2d ed., pp. 5, 325, etc.):-i. The Power of Discrimination; 2. The Power of Detecting Identity; 3. The Power of Retention. We exert the first power in every act of perception. Hardly can we have a sensation or feeling unless we discriminate it from something else which preceded. Consciousness would almost seem to consist in the break between one state of mind and the next, just as an induced current of electricity arises from the beginning or the ending of the primary current. We are always engaged in discrimination; and the rudiment of thought which exists in the lower animals probably consists in their power of feeling difference and being agitated by it. Yet had we the power of discrimination only, Science could not be created. To know that one feeling differs from another gives purely negative information. It cannot teach us what will happen. In such a state of intellect each sensation would stand out distinct from every other; there would be no tie, no bridge of affinity between them. We want a

unifying power by which the present and the future may be linked to the past; and this seems to be accomplished by a different power of mind. Lord Bacon has pointed out that different men possess in very different degrees the powers of discrimination and identification. It may be said indeed that discrimination necessarily implies the action of the opposite process of identification; and so it doubtless does in negative points. But there is a rare property of mind which consists in penetrating the disguise of variety and seizing the common elements of sameness; and it is this property which furnishes the true measure of intellect. The name of intellect' expresses the interlacing of the general and the single, which is the peculiar province of mind. (Max Müller, Lect. Sci. Lang., 2d series, Vol. II., p. 63).

Plato said of this unifying power, that if he met the man who could detect the one in the many, he would follow him as a god." (Jevons, The Princ. of Science, pp. 4-5, ed. 1877.)

66 LAWS OF IDENTITY AND DIFFERENCE.

182. "At the base of all thought and science must lie the laws which express the very nature and conditions of the discriminating and identifying powers of mind. These are the so-called Fundamental Laws of Thought, usually stated as follows:

1. The Law of Identity.

Whatever is, is. 2. The Law of Contradiction. A thing cannot both be and not be.

3. The Law of Duality. A thing must either be or not be.

"The first of these statements may perhaps be regarded as a description of identity itself, if so fundamental a notion can admit of description. A thing at any moment is perfectly identical with itself, and, if any person were unaware of the meaning of the word ' identity,' we could not better describe it than by such an example.

The

"The second law points out that contradictory attributes can never be joined together. same object may vary in its different parts; here it may be black, and there white; at one time it may be hard and at another time soft; but at the same time and place an attribute cannot be both present and absent. Aristotle truly described this law as the first of all axioms-one of which we need not seek for any demonstration. All truths cannot be proved, otherwise there would be an endless chain of demonstration; and it is in self-evident truths like this that we find the simplest foundations.

"The third of these laws completes the other two. It asserts that at every step there are two possible alternatives-presence or absence, affirmation or negation. Hence I propose to name this law the Law of Duality, for it gives to all the formulæ of reasoning a dual character. It asserts also that between presence and absence, existence and non-existence, affirmation and negation, there is no third alternative. As Aristotle said, there can be no mean between oppo

site assertions: we must either affirm or deny." (Ibid., pp. 5-6.)

66

183. The primitive and essential gradation of thought we have indicated to be the Judgment. In accordance with what has been said, a Judgment may be defined to be a recognition of the identity or non-identity between any two objects presented to the Faculty of Thought. As expressed in words, a Judgment is called a Proposition, or in grammatical nomenclature, a Sentence.

"Besides the Judgment, there are two other products of thought, both derivatives from the Judgment. The one is the Concept, which is derived from several Judgments by an act of Conceiving-taking together, in other words, by an act of synthesis. The other is the Reasoning, which is derived from one or more Judgments by an act of analysis or separation. As all thought is essentially a movement in Quantity, and as variations in Quantity can be affected only in the one or the other of these two directions, synthesis and analysis, the Concept and the Reasoning are the only conceivable derivatives from a Judgment, except such as consist only in variations of form, that do not affect the identity of the thought.

"In explication of this definition of a Judgment, it will be necessary simply to recall what has been already said in the exposition of the general nature of thought. As we have seen, a judgment necessarily supposes two objects;

and its essential characteristic, as an act of Intelligence, consists in this: that it is a cognition of this particular relation of identity or nonidentity between the two objects. These two objects of a judgment are given to it by some other faculty of the Intelligence, as of Perception, Intuition, Memory, or by the Discursive Faculty itself, in some previous exercise. It may be some object of Perception, as Bucephalus. As thus given by the Perceptive Faculty, the cognition is of an object by itself, without relation either to other objects or to the parts of the object itself. Color is not in the perception itself distinguished from figure; neither color nor figure from the position or the time in which it is perceived; and neither of these from the useful qualities of the object. All the perceptible qualities are given together without distinction in the presentation itself of the object. But when thus given, the mind at once, and by a kind of necessity of its being as essentially active and reflective, exerts its activity on it, first, by apprehending it as a part of a multiplicity of objects around, to each of which it stands in relation, and also, as a whole, containing parts in itself. This is the primitive and conditional gradation in all thought the apprehension of an object as a part or as a whole-in other words, in the relation of Quantity. Simultaneously with this, it apprehends some other object of thought given to it by Perception, or by some other Faculty of the Intelligence, or in some previous exercise of the