(2.) _The second fundamental principle_, conditioned in its content, and only unconditioned in its form, which is just as incapable as the first of demonstration or derivation, is also a fact of the empirical consciousness: it is the proposition non-A is not = A. This sentence is unconditioned in its form, because it is free act like the first, from which it cannot be derived; but in its content, as to its matter it is conditioned, because if a non-A is posited, there must have previously been posited an A. Let us examine this principle more closely. In the first principle, A = A, the form of the act was a positing, while in this second principle it is an oppositing. There is an absolute opposition, and this opposition, in its simple form, is an act absolutely possible, standing under no condition, limited by no higher ground. But as to its matter, the opposition presupposes a position; the non-A cannot be posited without the A. What non-A is, I do not through that yet know: I only know concerning non-A that it is the opposite of A: hence I only know what non-A is under the condition that I know A. But now A is posited through the Ego; there is originally nothing posited but the Ego, and nothing but this absolutely posited. Hence there can be an absolute opposition only to the Ego. That which is opposed to the Ego is the non-Ego. A non-Ego is absolutely opposed to the Ego, and this is the second fact of the empirical consciousness. In every thing ascribed to the Ego, the contrary, by virtue of this simple opposition, must be ascribed to the non Ego.—As we obtained from the first principle Ego = Ego, the logical law of identity, so now we have, from the second sentence Ego is not = non-Ego, the logical law of contradiction. And metaphysically,—since we wholly abstract the definite act of judgment, and, simply in the form of sequence, conclude not-being from opposite being,—we possess from this second principle the category of _negation_.