No determinate idea is united to the conception of being when we affirm the impossibility of a thing being and not-being at the same time, or the exclusion of not-being by being; and so far we absolutely abstract all sensible intuition. Whatever be its object, whatever its nature and the relations of its existence; be it corporeal or incorporeal, composite or simple, accident or substance, contingent or necessary, finite or infinite, always will it be found true that being excludes not-being; the absolute incompatibility of these two extremes will always be verified, so that the affirmation of the one is always, in all cases, and under all imaginable suppositions, the negation of the other. This being so, to limit the value of these conceptions to sensible intuition, would be to destroy the principle of contradiction. The limitation of the principle is equivalent to its nullification. Its absolute universality is closely allied to its absolute necessity; if it be curtailed, it is made contingent; for, if the principle of contradiction may fail us in one instance, it fails us in all. To admit the possibility of what is absurd, is to deny its absurdity. If the contradiction of being and not-being does not exist in every supposition, it exists in no supposition. 102. The difficulty is to know how the transition from the principle of contradiction to real truths, is made; because not affirming any thing determinate in it, but solely the repugnance of yes to no, and of no to yes, we assert that it would be impossible to affirm either one of these extremes without denying the other; and as on the other hand, it is impossible, if we confine ourselves to the principle of contradiction, for it to include any thing more than the most general relation between two general ideas, we conclude that it is of itself alone, perfectly sterile and unable to conduct us to any positive result. This is all true; but it contradicts in no point what we have said concerning the intrinsic value of general conceptions. We have remarked that truths of the purely ideal order have none but a hypothetical value, and that in order to produce a positive science, they require facts to which they may apply. We have also remarked, that experience furnishes these facts, and that every thinking being possesses one at least, consciousness of itself. Every thinking being will therefore, provided it discover in its own consciousness facts to which it may apply it, make a positive use of the principle of contradiction.