I. There is now no question of ascertaining whether the applications of the idea of being or reality beyond the sensible order be founded or unfounded; there is question only of ascertaining what it is that this idea represents to us, whether the object represented be illusory or not. Kant, when defining reality, regards it as one of his categories, and consequently, as one of the pure conceptions of the understanding. To make his definition good, he ought to employ this conception in its greatest possible extent: but as he has demonstrated that conception, in itself, is not limited to the sphere of sensibility, it must follow that his definition is inadmissible. Had he said that the applications of the conception beyond the sensible order were unfounded, he would indeed have erred, but would not have destroyed conception itself; yet he equivocates not only in the uses of conception, but also in its nature, which he can only ruin, if he limit it to the sphere of sensibility. II. The principle of contradiction is founded in the idea of being, and extends as well to the non-sensible as to the sensible. It would follow, were we to admit Kant's doctrine, that the principle of contradiction, "It is impossible for a thing to be and not to be at the same time," would be equivalent to this proposition; "It is impossible for a phenomenon of sensibility to appear and not to appear at the same time." Evidently neither philosophy nor common sense ever gave such a meaning to the principle of contradiction. When the impossibility of a thing's being and not being at the same time is affirmed, this is asserted in general, and abstraction is absolutely made of the things pertaining or not pertaining to the sensible order. Were it not thus, we should be obliged to say that non-sensible beings are absolutely impossible, which even Kant does not venture to maintain, or, supposing them to exist, to doubt whether the principle of contradiction is applicable to them. Who sees not the absurdity of such a doubt, and that, if it be admitted for a single instant, all intelligence is destroyed? If we limit the generality of the principle of contradiction, the impossibility is no longer absolute: and supposing it to fail in certain cases, who shall assure us that it does not in all? III. Kant himself admits the distinction between the phenomena of sensibility and purely intellectual conceptions: with him, therefore, reality comprises something more than the sensible. Purely intellectual conceptions are a reality, are something at least as subjective phenomena of our mind, and yet are not sensible, as Kant himself confesses; he therefore falls into a contradiction, when he limits the idea of reality to the purely sensible.