If we now return to the above question:--how does the law read, in obeying which, according to Kant, duty consists? and on what is it based?--we shall find that our philosopher, like most others, has in an extremely artificial manner closely connected the principle of Morals with its basis. I again call attention to what I have already examined at the outset--I mean, the Kantian claim that the principle of Ethics must be purely _a priori_ and purely formal, indeed an _a priori_ synthetical proposition, which consequently may not contain anything material, nor rest upon anything empirical, whether objectively in the external world, or subjectively in consciousness, such as any feeling, inclination, impulse, and the like. Kant was perfectly aware of the difficulty of this position; for on p. 60 (R., p. 53) he says: "It will be seen that philosophy has here indeed reached a precarious standpoint, which yet is to be immovable, notwithstanding that it is neither dependent on, nor supported by, anything in heaven or on earth." We shall therefore with all the greater interest and curiosity await the solution of the problem he has set himself, namely, how something is to arise out of nothing, that is, how out of purely _a priori_ conceptions, which contain nothing empirical or material, the laws of material human action are to grow up. This is a process which we may find symbolised in chemistry, where out of three invisible gases (Azote, Hydrogen, and Chlorine[9]), and thus in apparently empty space, solid sal-ammoniac is evolved before our eyes.