As pure intuitions, these forms are objects for the faculty of representation by themselves and apart from complete representations and from the determinations of being empty or filled which these representations first add to them; since even pure points and pure lines cannot be brought to sensuous perception, but are only _à priori_ intuitions, just as the infinite expansion and the infinite divisibility of Space and of Time are exclusively objects of pure intuition and foreign to empirical perception. That which distinguishes the third class of representations, in which Space and Time are _pure intuitions_, from the first class, in which they are _sensuously_ (and moreover conjointly) _perceived_, is Matter, which I have therefore defined, on the one hand, as the perceptibility of Space and Time, on the other, as objectified Causality. The form of Causality, on the contrary, which belongs to the Understanding, is not separately and by itself an object for our faculty of representation, nor have we consciousness of it, until it is connected with what is material in our knowledge. § 36. _Principle of the Sufficient Reason of Being._ Space and Time are so constituted, that all their parts stand in mutual relation, so that each of them conditions and is conditioned by another. We call this relation in Space, _position_; in Time, _succession_. These relations are peculiar ones, differing entirely from all other possible relations of our representations; neither the Understanding nor the Reason are therefore able to grasp them by means of mere conceptions, and pure intuition _à priori_ alone makes them intelligible to us; for it is impossible by mere conceptions to explain clearly what is meant by above and below, right and left, behind and before, before and after. Kant rightly confirms this by the assertion, that the distinction between our right and left glove cannot be made intelligible in any other way than by intuition. Now, the law by which the divisions of Space and of Time determine one another reciprocally with reference to these relations (position and succession) is what I call the _Principle of the Sufficient Reason of Being, principium rationis sufficientis essendi_. I have already given an example of this relation in § 15, by which I have shown, through the connection between the sides and angles of a triangle, that this relation is not only quite different from that between cause and effect, but also from that between reason of knowledge and consequent; wherefore here the condition may be called _Reason of Being_, _ratio essendi_. The insight into such a _reason of being_ can, of course, become a reason of knowing: just as the insight into the law of causality and its application to a particular case is the reason of knowledge of the effect; but this in no way annuls the complete distinction between Reason of Being, Reason of Becoming, and Reason of Knowing. It