Thus the schemata of the concepts of pure understanding are the true and sole conditions for providing them with a relation to objects/ thus with significance, and hence the categories are in the end of none but a possible empirical use, since they merely serve to subject appearances to general rules of syn thesis through grounds of an a priori necessary unity (on account of the necessary unification of all consciousness in an original apperception), and thereby to make them fit for a thoroughgoing connection in one experience.