The following important remark occurs here: There are _three kinds of Antinomies_ of pure Reason, which, however, all agree in this, that they compel us to give up the otherwise very natural hypothesis that objects of sense are things in themselves, and force us to regard them merely as phenomena, and to supply to them an intelligible substrate (something supersensible of which the concept is only an Idea, and supplies no proper knowledge). Without such antinomies Reason could never decide upon accepting a principle narrowing so much the field of its speculation, and could never bring itself to sacrifices by which so many otherwise brilliant hopes must disappear. For even now when, by way of compensation for these losses, a greater field in a practical aspect opens out before it, it appears not to be able without grief to part from those hopes, and disengage itself from its old attachment. That there are three kinds of antinomies has its ground in this, that there are three cognitive faculties,--Understanding, Judgement, and Reason; of which each (as a superior cognitive faculty) must have its _a priori_ principles. For Reason, in so far as it judges of these principles and their use, inexorably requires, in respect of them all, the unconditioned for the given conditioned; and this can never be found if we consider the sensible as belonging to things in themselves, and do not rather supply to it, as mere phenomenon, something supersensible (the intelligible substrate of nature both external and internal) as the reality in itself [Sache an sich selbst]. There are then: (1) _For the cognitive faculty_ an antinomy of Reason in respect of the theoretical employment of the Understanding extended to the unconditioned; (2) _for the feeling of pleasure and pain_ an antinomy of Reason in respect of the aesthetical employment of the Judgement; and (3) _for the faculty of desire_ an antinomy in respect of the practical employment of the self-legislative Reason; so far as all these faculties have their superior principles _a priori_, and, in conformity with an inevitable requirement of Reason, must judge and be able to determine their Object, _unconditionally_ according to those principles.