CHAP. V. SECT. III. from this we shall not at present consider; sufficient that we have now established the fact that we intuite a relation between relations. Predica tion not arbitrary. SECTION III. DEPENDENCE OF PREDICATION UPON INTUITION. $143. The connection of Predication with Intuition is not an arbitrary or fortuitous connection. A certain intuition having taken place, the predication which follows from it may not be this, or that, or something else, according to choice; but there are certain laws which govern us in founding mental assertions upon intuition. These laws may be very briefly stated and illustrated. We have before us various objects of intuition; they may be sensations, they may be objects of perception, they may be relations, or anything else immediately before consciousness. Let us indicate them by the first letters of the alphabet. We intuite the object A; it is necessary for us to predicate, "this is A;" it is impossible for us to predicate, "this is not A." This law of thought is usually known as the Axiom of Identity, and thus expressed: A is A, i.e., everything is what it is. Again, we intuite a certain relation existing between A and B. Upon this intuition is founded the predication "A is B;" and it is impossible for us to predicate "A is not B." This is usually called the Contradic- Axiom of Contradiction; and its formula is, Predica Law of tion. tions opposed contradictorily to each other cannot both be true. The one or the other must be false, and from the truth of the one follows the falsehood of the other. These two axioms express the nature of the dependence of predication upon intuition. They are simply an analytic statement of the principle that predication must in all cases be conformable to the intuition on which it is founded. Whatever is given in intuition must be asserted in predication; and it is a mental impossibility to assert the opposite of what is given in intuition. If the assertion be made in words, the mind refuses to acknowledge its truth. CHAP. V. SECT. III. truth. § 144. These two laws of the dependence of Test of predication upon intuition furnish us with the ultimate test of truth. That predication which is exactly conformable to the intuition of which it is an expression must be true. Intuition is to us the only perfectly trustworthy source of truth. If we are immediately conscious of any object, it is impossible for us to doubt the existence of that object, because there is no more authoritative or trustworthy source of information than consciousness. When, therefore, we intuite any of those objects which, we have seen, are given in intuition, we are compelled to recognise them as existing as they are known; there is no room, or no reason whatever, for doubting. And when, from this intuition, the predication has been made according to the above-mentioned laws, we accept it as true; we cannot help it. § 145. Notwithstanding the absolute certainty of this test of truth, if properly applied, a great deal of CHAP. V. SECT. III. Errors in applying test. error has crept into human belief. Arising from the application of these laws, the error may have two sources; it may arise from supposing some mental act to be an intuition which is not really so; or it may arise from forming some predication which does not exactly express what is given in the intuition. As an example of the former we may take the metaphysical doctrine of substance or substratum. It has been thought by many that the substance in which phenomenal qualities are supposed to inhere is made known to us in an act of intuition. But nothing can be farther from the truth; in itself, it is admittedly absolutely unknown; and, in fact, it is only one of several hypotheses which have been invented for the purpose of explaining the existence and objective unity of phenomena. To connect substance with intuition is, therefore, to give to intuition an entirely different meaning from what we consider to be the correct one. Generally speaking, both of the sources of error to which we have referred are most prolific in connection with acts of knowledge of a complex kind. Where the object of knowledge is very complex, or where the mental act is the result of some acquired power, it is not easy to discover what are the simple original intuitions, and, consequently, there is abundant room for error. But when we have before us an object which we know is directly given to us in an intuition, and when the predication is made in accordance with the laws of truth, there is, to our minds, no possibility of doubt. CHAP. V. SECT. IV. SECTION IV. THE CLASS; THE CONCEPT; THE NAME. how § 146. We have hitherto been concerned with Objects, individual objects of knowledge and the relations known. existing between them. We must now consider a mental process in which the individual objects that we know are variously joined together into classes. And it must be borne in mind that, in this connection, when we speak of objects, we mean not merely objects of simple intuition, but also objects or results of more complex mental processes, such as perception. Our knowledge of any object is made up of all the predications which we can form regarding it. Having perceived any object, we express our knowledge of it by predicating that it possesses such and such various qualities. And, in the case of each predication, we mean that the quality referred to in it exists in a certain relation to the aggregate of the other qualities contained in the other predications. Now, in considering any object of thought, we are able to restrict our attention to only a limited number of the qualities of which it is an aggregate; to separate them in imagination from the rest, and consider them by themselves. The qualities to which attention is thus exclusively given are said to be abstracted from the others. § 147. The power of restricted attention being Classes. admitted, we further postulate an ability to compare Р CHAP. V. SECT. IV. Concepts. different objects of knowledge with reference to the possession of abstracted qualities. Having a number of objects before us, we can, by observation, ascertain whether they all possess, or do not possess, a certain quality or qualities to which we have given attention. If we find that they all actually possess this quality, or these qualities, we naturally attribute to them a kind of unity; we think of them as forming a class; we apply to them some common name. Thus, the reason why we collect individual objects into classes, and designate them by a common name, is that we are able to predicate concerning them all some specified quality or qualities. Now, in this process there are three things to which we must give attention: first, the abstracted qualities; second, the class which has been constituted by virtue of the possession of these qualities; and third, the use and meaning of the name. § 148. In order that the process of generalisation may be possible, it is absolutely necessary that our attention should be restricted to some of the qualities of bodies; because, amongst the bodies with which we are acquainted, variety is uniformly to be found, and in order to reduce them to unity we must disregard the qualities in which they differ. Having, therefore, by observation abstracted certain specified qualities in the possession of which a number of objects agree, these qualities taken together form a kind of mental object; in the act of representation, although we may not be able to banish altogether all the other qualities of the bodies, yet we give to them peculiar prominence; we attribute to them a kind |