If, therefore, space (and time as well) were not a mere form of your intuition that contains a priori conditions under which alone things could be outer objects for you, which are nothing in themselves without these subjective conditions, then you could make out absolutely nothing synthetic and a priori about outer objects.c, It is therefore in dubitably certain, and not merely possible or even probable, that space and time, as the necessary conditions of all (outer and inner) experience, are merely subjective conditions of all our intuition, in relationd to which therefore all objects are mere appearances and not things given for themselves in this way; about these appearances, further, much may be said a priori that concerns their form, but nothing whatsoever about the things in themselves that may ground them.'