I do not in the least augment the object of my conception by the addition of the statement: This thing exists. Otherwise, not exactly the same, but something more than what was cogitated in my conception, would exist, and I could not affirm that the exact object of my conception had real existence. If I cogitate a thing as containing all modes of reality except one, the mode of reality which is absent is not added to the conception of the thing by the affirmation that the thing exists; on the contrary, the thing exists—if it exist at all—with the same defect as that cogitated in its conception; otherwise not that which was cogitated, but something different, exists. Now, if I cogitate a being as the highest reality, without defect or imperfection, the question still remains—whether this being exists or not? For, although no element is wanting in the possible real content of my conception, there is a defect in its relation to my mental state, that is, I am ignorant whether the cognition of the object indicated by the conception is possible a posteriori. And here the cause of the present difficulty becomes apparent. If the question regarded an object of sense merely, it would be impossible for me to confound the conception with the existence of a thing. For the conception merely enables me to cogitate an object as according with the general conditions of experience; while the existence of the object permits me to cogitate it as contained in the sphere of actual experience. At the same time, this connection with the world of experience does not in the least augment the conception, although a possible perception has been added to the experience of the mind. But if we cogitate existence by the pure category alone, it is not to be wondered at, that we should find ourselves unable to present any criterion sufficient to distinguish it from mere possibility.
Whatever be the content of our conception of an object, it is necessary to go beyond it, if we wish to predicate existence of the object. In the case of sensuous objects, this is attained by their connection according to empirical laws with some one of my perceptions; but there is no means of cognizing the existence of objects of pure thought, because it must be cognized completely a priori. But all our knowledge of existence (be it immediately by perception, or by inferences connecting some object with a perception) belongs entirely to the sphere of experience—
