If there did not lie in you a faculty for intuiting a priori; if this subjective condition regarding form were not at the same time the universal a priori condition under which alone the object of this (outer) intuition is itself possible; if the object (the triangle) were something in itself without relation to your subject: then how could you say that what necessarily lies in your subjective con ditions for constructing a triangle must also necessarily pertain to the triangle in itself?b