But since in us a certain form of sensible intuition a priori is fundamental, which rests on the receptivity of the capacity for representation (sensibility), the understanding, as spontaneity, can determine the manifold of given rep resentations in accord with the synthetic unity of apperception, and thus think a priori synthetic unity of the apperception of the manifold of sensible intuition, as the condition under which all objects of our (human) intuition must necessarily stand, through which then the cate gories, as mere forms of thought, acquire objective reality,.e., application to objects that can given to us in intuition, but only as appear ances; for of these alone are we capable of intuition a priori.