§ 3.

The main difference among all our representations is that between the intuitive and the abstract. The latter constitutes only one class of representations, namely concepts; and on earth these are the property of man alone. The capacity for these which distinguishes him from all animals has at all times been called reason (Vernunft).13 We shall consider further these abstract representations by themselves, but first of all we shall speak exclusively of the intuitive representation. This embraces the entire visible world, or the whole of experience, together with the conditions of its possibility. As we have said, it is one of Kant’s very important discoveries that these very conditions, these forms of the visible world, in other words, the most universal element in its perception, the common property of all its phenomena, time and space, even by themselves and separated from their content, can be not only thought in the abstract, but also directly perceived. This perception or intuition is not some kind of phantasm, borrowed from experience through repetition, but is so entirely independent of experience that, on the contrary, experience must be thought of as dependent on it, since the properties of space and time, as they are known in a priori perception or intuition, are valid for all possible experience as laws. Everywhere experience must turn out in accordance with these laws. Accordingly, in my essay On the Principle of Sufficient Reason, I have regarded time and space, in so far as they are perceived pure and empty of content, as a special class of representations existing by itself. Now this quality of those universal forms of intuition, discovered by Kant, is certainly very important, the quality, that is, that they are perceivable in themselves and independently of experience, and are knowable by their entire conformity to law, on which rests mathematics with its infallibility. Not less remarkable, however, is the quality of time and space that the principle of sufficient reason, which determines experience as the law of causality and of motivation, and thought as the law of the basis of judgements, appears in them in quite a special form, to which I have given the name ground of being. In time this is the succession of its moments, and in space the position of its parts, which reciprocally determine one another to infinity.

Anyone who has clearly seen from the introductory essay the complete identity of the content of the principle of sufficient reason, in. spite of all the variety of its forms, will also be convinced of the importance of the knowledge of the simplest of its forms as such for an insight into his own inmost nature. We have recognized this simplest form to be time. In time each moment is, only in so far as it has effaced its father the preceding moment, to be again effaced just as quickly itself. Past and future (apart from the consequences of their content) are as empty and unreal as any dream; but present is only the boundary between the two, having neither extension nor duration. In just the same way, we shall also recognize the same emptiness in all the other forms of the principle of sufficient reason, and shall see that, like time, space also, and like this, everything that exists simultaneously in space and time, and hence everything that proceeds from causes or motives, has only a relative existence, is only through and for another like itself, i.e., only just as enduring. In essence this view is old; in it Heraclitus lamented the eternal flux of things; Plato spoke with contempt of its object as that which for ever becomes, but never is; Spinoza called it mere accidents of the sole substance that alone is and endures; Kant opposed to the thing-in-itself that which is known as mere phenomenon; finally, the ancient wisdom of the Indians declares that “it is Mâyâ, the veil of deception, which covers the eyes of mortals, and causes them to see a world of which one cannot say either that it is or that it is not; for it is like a dream, like the sunshine on the sand which the traveller from a distance takes to be water, or like the piece of rope on the ground which he regards as a snake.” (These similes are repeatedly found in innumerable passages of the Vedas and Puranas. ) But what all these meant, and that of which they speak, is nothing else but what we are now considering, namely the world as representation subordinated to the principle of sufficient reason.