PSYCHOLOGY 79 by suppressing all the several notes in a tune. They are not primarily concepts more general than all others in the sense in which animal is more general than man, but rather distinct methods of relating or synthesizing presentations. Kant, though he accepted almost unquestioned the logic and psychology current in his day, has yet been the occa- sion, in spite of himself, of materially advancing both, and chiefly by the distinction he was led to make between formal and transcendental logic. In his exposition of the latter he brings to light the difference between the " functions of the understanding " in synthesizing or, as we might say, organizing percepts into concepts and the merely analytic subsumption of abc and abd under ab, a, 6, c, and d being what they may. Unlike other concepts, categories as such do not in the first instance signify objects of thought how- ever general, but these functions of the understanding in constituting objects. In fine, they all imply some special process, and into these processes it is the business of psychology to inquire. But only the briefest attempt at such inquiry is here possible. To begin with what are par excellence formal categories, and among these with that which is the most fundamental and formal of all How do we come by the conception of unity 1 " Amongst all the ideas we have," says Locke, " as there is none suggested to the mind by more ways, so there is none more simple than that of unity, or one. It has no shadow of variety or composition in it ; every object our senses are employed about, every idea in our understand- ings, every thought of our minds, brings this idea along with it." 1 And the like with painful iteration has been said by almost all English psychologists since. Such con- sensus notwithstanding, to assign a sensible origin to unity is certainly a mistake, one of a class of mistakes already more than once referred to, which consist in transferring to the data of sense all that is implied in the language necessarily used in speaking of them. The term "a sensa- tion " no doubt carries along with it the idea of unity, but the bare sensation as received brings along with it nothing but itself. And, if we consider sensory consciousness merely, we do not receive a sensation, and then another sensation, and so on seriatim ; but we have always a con- tinuous diversity of sensations even when these are quali- tatively sharply differentiated. Moreover, if unity were an impression of sense and passively received, it would, in common with other impressions, be unamenable to change. We cannot see red as blue, but we can resolve many (parts) into one (whole), and vice versa? Unity, then, is the result of an act the occasions for which, no doubt, are at first non- voluntarily determined ; but the act is still as distinct from them as is attention from the objects attended to. It is to that movement of attention already described in dealing with ideation (p. 61) that we must look as the source of this category. This same movement, in like manner, yields us temporal signs ; and the complex unity formed by a combination of these is what we call number. When there is little or no difference between the field and the focus of attention, unifying is an impossibility, whatever the impressions received may be. On the other hand, as voluntary acts of concentration become more fre- quent and distinct the variegated continuum of sense is shaped into intuitions of definite things and events. Also, as soon as words facilitate the control of ideas, it becomes possible to single out special aspects and relations of 1 Essay concerning Human Understanding, II. xvi. 1. 2 " Wir konnen eines der hier gedruckten Wdrter als Eins ansehen, indem wir eine Mannigfaltigkeit von Buchstaben doch in einem ab- schliessenden Acte zu eiueni Bilde vereinigen und es von den benach- barten Bildern trennen ; wir konnen es als Vielheit ansehen, wenn wir auf den Uebergang von einem Buchstaben zum andern, jeden Schritt absetzend, achten " (Sigwart, Logik, ii. p. 41). things as the subjects or starting-points of our dis- cursive thinking. Thus the forms of unity are manifold: every act of intuition or thought, whatever else it is, is an act of unifying. It is obvious that the whole field of consciousness at any moment can never be actually embraced as one. What is unified becomes thereby the focus of consciousness and so leaves an outlying field ; so far unity may be held to imply plurality. But it cannot with propriety be said that in a simple act of attention the field of consciousness is analysed into two distinct parts, i.e., two unities, this (now attended to) and the other or the rest (abstracted from). For the not-this is but the rest of a continuum and not itself a whole ; it is left out but not determined, as the bounding space is left out when a figure is drawn. To know two unities we must connect both together ; and herein comes to light the difference between the unity which is the form of the concept or subject of discourse and the unity of a judgment. The latter is of necessity complex ; the former may or may not be. But in any case the complexity of the two is different. If the subject of thought is not only clear but distinct i.e., not merely defined as a whole but having its constituents likewise more or less defined such distinctness is due to previous judgments. At any future time these may of course be repeated ; such are the ana- lytical or explicative judgments of logic. As the mere subject of discourse it is, however, a single unity simul- taneously apprehended ; the relation ascertained between it and its predicate constitutes the unity of judgment, a unity which is comprehended only when its parts are successively apprehended. But, though a judgment is always a complex unity, the Law of extent of this complexity seems at first sight to vary as the form of synthesis varies. Formal logic, as we seen, by throwing the form of synthesis into the predicate has no difficulty in reducing every judgment to an S is P. But, if we at all regard the matter thought, it is certain, for example, that " It is an explosion " is less complex than " The enemy explodes the mine." The first answers one question ; the second answers three. But as regards the more complex judgment both the process of ascertaining the fact and the language in which it is expressed show that the three elements concerned in it are not synthesized at once. Suppose we start from the explosion, and changes or movements are not only apt to attract attention first, but, when recognized as events and not as abstracts per- sonified, they call for some supplementing beyond them- selves then in this case we may search for the agent at work or for the object affected, but not for both at once. Moreover, if we find either, a complete judgment at once ensues : " The enemy explodes," or " The mine is exploded." The original judgment is really due to a synthesis of these two. But, when the results of former judgments are in this manner taken up into a new judgment, a certain " condensation of thought " ensues. Of this condensation the grammatical structure of language is evidence, though logical manipulation with great pains obliterates it. Thus our more complex judgment would take the form "The enemy is now mine -exploding" or "The mine is enemy-exploded," according as one or other of the simpler judgments was made first. An examination of other cases would in like manner tend to show that intellectual synthesis is always in itself and apart from implications a binary synthesis. Wundt, to whom belongs the merit of first explicitly stating this "law of dichotomy or duality" 3 as the cardinal principle of discursive thinking, contrasts it with synthesis by mere association. This, as running on continuously, he represents thus A~B~C~D~ . . . ; the 3 Wundt, Logik : eine Untersuchung der Principien der Erkenntniss, i. p. 53 sq.
