sensualizing this invisible again; that is to say, wanting to make it an object of intuition, so that they do not become a whit the wiser. Now man really finds in himself a faculty by which he distinguishes himself from everything else, even from himself as affected by objects, and that is reason. This being pure spontaneity is even elevated above the understanding. For although the latter is a spontaneity and does not, like sense, merely contain intuitions that arise when we are affected by things (and are therefore passive), yet it cannot produce from its activity any other conceptions than those which merely serve to bring the intuitions of sense under rules and, thereby, to unite them in one consciousness, and without this use of the sensibility it could not think at all; whereas, on the contrary, reason shows so pure a spontaneity in the case of what I call ideas [ideal conceptions] that it thereby far transcends everything that the sensibility can give it, and exhibits its most important function in distinguishing the world of sense from that of understanding, and thereby prescribing the limits of the understanding itself. For this reason a rational being must regard himself qua intelligence (not from the side of his lower faculties) as belonging not to the world of sense, but to that of understanding; hence he has two points of view from which he can regard himself, and recognise laws of the exercise of his faculties, and consequently of all his actions: first, so far as he belongs to the world of sense, he finds himself subject to laws of nature (heteronomy); secondly, as belonging to the intelligible world, under laws which being independent of nature have their foundation not in experience but in reason alone. As a rational being, and consequently belonging to the intelligible world, man can never conceive the causality of his own will otherwise than on condition of the idea of freedom, for independence of the determinate causes of the sensible world (an independence which reason must always ascribe to itself) is freedom. Now the idea of freedom is inseparably connected with the conception of autonomy, and this again with the universal principle of morality which is ideally the foundation of all actions of rational beings, just as the law of nature is of all phenomena.