If we follow the latter order, it is a FUNDAMENTAL PROPOSITION to which even the commonest human Reason is compelled to give immediate assent, that if there is to be in general a _final purpose_ furnished _a priori_ by Reason, this can be no other than _man_ (every rational being of the world) _under moral laws_.[133] For (and so every one judges) if the world consisted of mere lifeless, or even in part of living but irrational, beings, its existence would have no worth because in it there would be no being who would have the least concept of what worth is. Again, if there were intelligent beings, whose Reason were only able to place the worth of the existence of things in the relation of nature to themselves (their well-being), but not to furnish of itself an original worth (in freedom), then there would certainly be (relative) purposes in the world, but no (absolute) final purpose, because the existence of such rational beings would be always purposeless. But the moral laws have this peculiar characteristic that they prescribe to Reason something as a purpose without any condition, and consequently exactly as the concept of a final purpose requires. The existence of a Reason that can be for itself the supreme law in the purposive reference, in other words the existence of rational beings under moral laws, can therefore alone be thought as the final purpose of the being of a world. If on the contrary this be not so, there would be either no purpose at all in the cause of its being, or there would be purposes, but no final purpose. The moral law as the formal rational condition of the use of our freedom obliges us by itself alone, without depending on any purpose as material condition; but it nevertheless determines for us, and indeed _a priori_, a final purpose towards which it obliges us to strive; and this purpose is the _highest good in the world_ possible through freedom. The subjective condition under which man (and, according to all our concepts, every rational finite being) can set a final purpose before himself under the above law is happiness. Consequently, the highest physical good possible in the world, to be furthered as a final purpose as far as in us lies, is _happiness_, under the objective condition of the harmony of man with the law of _morality_ as worthiness to be happy. But it is impossible for us in accordance with all our rational faculties to represent these two requirements of the final purpose proposed to us by the moral law, as _connected_ by merely natural causes, and yet as conformable to the Idea of that final purpose. Hence the concept of the _practical necessity_ of such a purpose through the application of our powers does not harmonise with the theoretical concept of the _physical possibility_ of working it out, if we connect with our freedom no other causality (as a means) than that of nature.