Finally, a concept may also be used in order to arrive by means of it at a definite particular idea of perception, from which, as well as from many others, this concept itself is drawn; this happens in the singular judgment. Such a judgment merely indicates the boundary-line between abstract knowledge and knowledge of perception, and passes directly to the latter, “This tree here bears gall-nuts.” Kant has made of this also a special category.
After all that has been said there is no need of further polemic here.
2. In the same way the _Quality_ of the judgment lies entirely within the province of reason, and is not an adumbration of any law of that understanding which makes perception possible, _i.e._, it does not point to it. The nature of abstract concepts, which is just the nature of the reason itself objectively comprehended, carries with it the possibility of uniting and separating their spheres, as was already explained in the first book, and upon this possibility, as their presupposition, rest the universal laws of thought of identity and contradiction, to which I have given the name of _metalogical_ truths, because they spring purely from the reason, and cannot be further explained. They determine that what is united must remain united, and what is separated must remain separate, thus that what is established cannot at the same time be also abolished, and thus they presuppose the possibility of the combination and separation of spheres, _i.e._, of judgment. This, however, lies, according to its _form_, simply and solely in the reason, and this _form_ has not, like the _content_ of the judgments, been brought over from the perceptible knowledge of the understanding, and therefore there is no correlative or analogue of it to be looked for there. After the perception has been brought about through the understanding and for the understanding, it exists complete, subject to no doubt nor error, and therefore knows neither assertion nor denial; for it expresses itself, and has not, like the abstract knowledge of the reason, its value and content in its mere relation to something outside of it, according to the principle of the ground of knowing. It is, therefore, pure reality; all negation is foreign to its nature, can only be added on through reflection, and just on this account remains always in the province of abstract thought.