On the Fourfold Root of the Principle of Sufficient...

Now as, notwithstanding this union through the Understanding of the forms of the inner and outer sense in representing Matter and with it a permanent outer world, all immediate knowledge is nevertheless acquired by the Subject through the inner sense alone—the outer sense being again Object for the inner, which in its turn perceives the perceptions of the outer—and as therefore, with respect to the immediate presence of representations in its consciousness, the Subject remains under the rule of Time alone, as the form of the inner sense:[56] it follows, that only one representation can be present to it (the Subject) at the same time, although that one may be very complicated. When we speak of representations as immediately present, we mean, that they are not only known in the union of Time and Space effected by the Understanding—an intuitive faculty, as we shall soon see—through which the collective representation of empirical reality arises, but that they are known in mere Time alone, as representations of the inner sense, and just at the neutral point at which its two currents separate, called the present. The necessary condition mentioned in the preceding paragraph for the immediate presence of a representation of this class, is its causal action upon our senses and consequently upon our organism, which itself belongs to this class of objects, and is therefore subject to the causal law which predominates in it and which we are now about to examine.

Now as therefore, on the one hand, according to the laws of the inner and outer world, the Subject cannot stop short at that one representation; but as, on the other hand, there is no coexistence in Time alone: that single representation must always vanish and be superseded by others, in virtue of a law which we cannot determine à priori, but which depends upon circumstances soon to be mentioned. It is moreover a well-known fact, that the imagination and dreams reproduce the immediate presence of representations; the investigation of that fact, however, belongs to empirical Psychology. Now as, notwithstanding the transitory, isolated nature of our representations with respect to their immediate presence in our consciousness, the Subject nevertheless retains the representation of an all-comprehensive complex of reality, as described above, by means of the function of the Understanding; representations have, on the strength of this antithesis, been viewed, as something quite different when considered as belonging to that complex than when considered with reference to their immediate presence in our consciousness. From the former point of view they were called real things; from the latter only, representations κατ' ἐξοχήν. This view of the matter, which is the ordinary one, is known under the name of Realism. On the appearance of modern philosophy, Idealism opposed itself to this Realism and has since been steadily gaining ground.

Malebranche and Berkeley were its earliest representatives, and Kant enhanced it to the power of Transcendental Idealism, by which the co-existence of the Empirical Reality of things with their Transcendental Ideality becomes conceivable, and according to which Kant expresses himself as follows:[57] "Transcendental Idealism teaches that all phenomena are representations only, not things by themselves." And again:[58] "Space itself is nothing but mere representation, and whatever is in it must therefore be contained in that representation. There is nothing whatever in Space, except so far as it is really represented in it." Finally he says:[59] "If we take away the thinking Subject, the whole material world must vanish; because it is nothing but a phenomenon in the sensibility of our own subject and a certain class of its representations." In India, Idealism is even a doctrine of popular religion, not only of Brahminism, but of Buddhism; in Europe alone is it a paradox, in consequence of the essentially and unavoidably realistic principle of Judaism. But Realism quite overlooks the fact, that the so-called existence of these real things is absolutely nothing but their being represented (ein Vorgestellt-werden), or—if it be insisted, that only the immediate presence in the consciousness of the Subject can be called being represented κατ' ἐντελέχειαν—it is even only a possibility of being represented κατὰ δύναμιν.

The realist forgets that the Object ceases to be Object apart from its reference to the Subject, and that if we take away that reference, or think it away, we at once do away with all objective existence. Leibnitz, while he clearly felt the Subject to be the necessary condition for the Object, was nevertheless unable to get rid of the thought that objects exist by themselves and independently of all reference whatsoever to the Subject, i.e. independently of being represented. He therefore assumed in the first place a world of objects exactly like the world of representations and running parallel with it, having no direct, but only an outward connection with it by means of a harmonia præstabilita;—obviously the most superfluous thing possible, for it never comes within perception, and the precisely similar world of representations which does come within perception, goes its own way regardless of it. When, however, he wanted to determine more closely the essence of these things existing objectively in themselves, he found himself obliged to declare the Objects in themselves to be Subjects (monades), and by doing so he furnished the most striking proof of the inability of our consciousness, in as far as it is merely cognitive, to find within the limits of the intellect—i.e. of the apparatus by means of which we represent the world—anything beyond Subject and Object; the representer and the represented.

Therefore, if we abstract from the objectivity of an Object, or in other words, from its being represented (Vorgestellt-werden), if we annul it in its quality as an Object, yet still wish to retain something, we can meet with nothing but the Subject. Conversely, if we desire to abstract from the subjectivity of the Subject, yet to have something over, the contrary takes place, and this leads to Materialism.

Spinoza, who never thoroughly sifted the matter, and never therefore acquired a clear notion of it, nevertheless quite understood the necessary correlation between Subject and Object as so essential, that they are inconceivable without it; consequently he defined it as an identity in the Substance (which alone exists) of that which knows, with that which has extension.

Observation.—With reference to the chief argument of this paragraph, I take the opportunity to remark that if, in the course of this treatise, for the sake of brevity and in order to be more easily understood, I at any time use the term real objects, I mean by it nothing but the intuitive representations that are united to form the complex of empirical reality, which reality in itself always remains ideal.