springing from the temporal order in which sensations are given, is the source of the causal relation; and, except for the case of demonstrative reasoning, it is the foundation of all inference. It is this, which, as Berkeley says, "gives us a sort of foresight which enables us to regulate our actions for the benefit of life." And Hume expressly holds that "the only connection or relation of objects, which can lead us beyond the immediate impressions of our memory and senses, is that of cause and effect." The basis of syllogistic inference is, of course, different. This is to be found in that extraordinary faculty of comparison which plays so great a part in the classic empiricism.

But the importance of this exception must not be exaggerated. Hume's criticism of the notion of the self, resolving it into a mere sensational complex, strikes a death-blow at the conception of an act of the mind. Though he himself may not admit it, the possibility of an "arbitrary union of two ideas in the fancy," "without a connecting principle," has disappeared. The faculty of comparison, like all other faculties, must be explained in terms of the natural behavior of the ideas themselves. Thus empiricism takes the form of a pure associationism—and thus the identity of the causal and the logical orders becomes complete.

CHAPTER IV

THE REPRESENTATIVE THEORY OF IDEAS

Some remarkable illustrations of the doctrines set forth in the preceding chapters are connected with the representative theory of ideas, or 'epistemological dualism,' as it has latterly been called. And so, though this theory is by no means universally accepted by the old dogmatists, we think it important to give some analysis of it, and to show its relation to rationalism and empiricism respectively. A general definition of the theory, which will apply with perfect justice to all of the various forms which it has taken, probably cannot be given. But an approximation, which will serve to introduce the present brief survey, may be based upon the following statement:

The things of which we have knowledge are not, as known, themselves present to consciousness, but are represented by ideas, with which they stand in a relation which is external to both or, at least, to the things.

By the concluding words it is implied, that, whatever the relation denoted by 'representation' may be, it neither is, nor affects, any part of the essential nature of the thing or (generally speaking) of the idea. The idea may be completely analyzed without betraying the existence of the thing; and the thing may exist in the full possession of its attributes though no idea of it ever arises. The correctness (truth, adequacy) of the idea and the 'cognizedness' of the thing are purely accidental. The words, “as known," imply that even an idea, in order to become object of knowledge, must be represented in consciousness by an idea of itself.

The simplest form of the theory, and the one from which all others are divergences, is that the idea is like the thing. This does not mean that the acceptance of an idea as correct is held

to imply that an actual comparison between the two has been made. On the contrary, no such comparison is believed to be possible at least to men. Even the case of an idea of an idea is no exception. Nothing can be known except through a representative—not even a representative. The utmost that comparison can do is to equate one idea with another already accepted as correct. The meaning of the correctness therefore is that if (as is inconceivable) a comparison were made, the idea would be found to be like the thing.

This primitive theory is in most highly developed rationalisms recognized as out of the question; and it slips in only surreptitiously, as a relic of bygone habits of thought. In its place arises the theory, that the representation of things by ideas means not the resemblance of ideas to objects, but-the identity of the relations between ideas with those between objects. That is to say, the world of things is supposed to form a system, which is exactly paralleled by the system of true ideas; and the correspondence of an idea to a thing means that it is related to all other true ideas precisely as the thing is related to all other things. In a previous chapter we have shown how rationalism tends to reduce all relations to the one of logical inclusion. The system. of things then takes the form of a network of interlacing lines of causes and effects; and the system of ideas, one of subjects and predicates (or premises and conclusions). Among empiricists, too, the resemblance-theory cannot long maintain its ground -Berkeley's refutation of it is proof of that. As alternatives we find on the one hand a feeble reflection of the rationalistic doctrine—the theory of secondary qualities—and on the other hand, in all mature empiricisms, the rejection of the representative theory altogether. For the subjective idealism of Berkeley, by declaring that things are merely a class of ideas, amounts to a point-blank denial of the representative theory; and Hume's peculiar realism is so far in full agreement with Berkeley. For though 'images' (to use Berkeley's terminology) resemble ‘real things,' and do indeed represent them in their absence, the 'real

things' are themselves directly perceived; and the 'images' can be compared with the 'real things' and thus corrected by them. The representative theory in all its forms contains the following difficulty. On the one hand, there is nothing in the idea by which its correspondence with the thing, or even the existence of the thing, can be attested; and yet, on the other hand, it is only through the idea that the existence and nature of the thing can be known. The difficulty is evaded somewhat as follows. It is not anything in the idea (i. e., it is no part of its logical content, or of its psychological structure) that indicates its correctness, but some character that can vary independently of the content or structure. Thus the empiricist observes that sensations (as over against the precisely similar ideas of imagination) are distinguished by a peculiar intensity, steadiness, vividness, or emotional setting, or by their direct dependence upon the senseorgans; and any or all of these may be regarded as assuring the correctness of this class of ideas. On the other hand, the rationalist, rejecting the evidence of the senses, may specify the analytical distinctness of the true ideas as the distinguishing mark. If a ground be sought for any such theory, the empiricist who maintains it can only appeal to the observed fact, that such ideas as he has named cannot be doubted. The inability to doubt may be ascribed to two causes: the fixity of the idea itself in consciousness, or the strength of the feeling of conviction which accompanies it. That a similar procedure is possible to rationalism the example of Descartes shows. With him too the inability to doubt is the ultimate proof of a true idea. His famous criterion of truth is found inductively-by the method of difference, in fact. Having discovered an indubitable truth, he observes in what respect this differs from all the ideas which he has previously rejected as open to question; and this difference is then the criterion. Descartes, however, adopts this position only as the point of departure from which to reach a higher one. Ultimately, as he believes, the ground of the criterion is to be found in the veracity of God. The existence of a perfect being is thus a self

supporting truth on which all other truth depends.1 Needless to say, this is the more characteristically rationalistic position.

The epistemological dualism of idea and ideatum passes over very easily into an ontological dualism of mind and matter. The ideas are regarded as modes of thinking substance, and those ideata, which are not themselves ideas, are regarded as modes of extended substance. This is, of course, what we find in Descartes and (substantially) in Locke. But other ontological interpretations are by no means impossible. The distinction between idea and ideatum may be regarded as defining, not two kinds of substance, but two kinds of existence; that is to say, a single reality may be regarded as existing both as idea and as thing-objectively and subjectively. This is the conception which underlies the ontological proof of the existence of God in its original medieval form; for the proof turns upon the principle, that, since that which exists both as idea and as thing is more perfect than that which exists as idea alone, the most perfect being cannot be conceived as having the former kind of existence alone. In the period with which we are dealing, this conception is represented by Spinoza, by whom, however, it is carried to an extreme. Not only may the same reality exist both as idea and as thing, but nothing can exist otherwise. There is but one substance, which in each of its modes exists both as idea and as thing, that is to say, in the attributes of thinking and extension. The correspondence between idea and thing is, therefore, a universal parallelism; and if, to a superficial reflection, this does not appear to be the case, that is only because ideas are confused. All error is confusion. Every distinct idea (including, of course, every simple idea) is true; and the real content of every confused idea is likewise true. Truth here means the correspondence, not of one entity with another,

1It should be recalled that the ontological proof of the existence of God, in the form which Descartes gives it, is not a proof-that is to say, a deduction—in the ordinary sense of the term at all. It is a piece of exposition, calling attention to the fact, that the judgment that God exists is analytical and therefore requires no deduction. "Its conclusion may be known without proof by those who are free from all prejudice." Cf. Proposition I of the "geometrical" account of the proofs of God's existence, in the Reply to the Second Objections.