The world of sense contains nothing but appearances, but these are mere representations, which are once again always sensibly conditioned, and, since here we never have to do with things in themselves as our objects, it is no wonder that we are never justified in making a leap from one member of the empirical series, whatever it might be, outside the connections of sensibility, just as if these members were things in themselves existing outside their transcendental ground, which one might leave behind in seeking the cause of their existence outside them selves; of course that would have to happen with contingent things, but not with mere representations of things, whose contingency itself is only a phenomenon, and can lead to no other regress but the one de termining phenomena,.e.