Kant himself realised the need of some other standard for appraising human conduct. With such a purpose he arrived at his well-known maxim:—“Let your conduct be such that your motive might serve as a standard of universal application.” To explain the maxim he gave a number of examples. A man who is without money and cannot pay a debt is in doubt as to whether he should promise to repay his creditor. According to Kant, he ought to ask himself what would be the result if such a promise were to be made under similar circumstances by everyone. It is plain that if such false promises became universal, they would cease to be believed and so would be impracticable in actual life. Kant’s formula, therefore, would supply a rational basis for the discrimination of immoral conduct. In the case of theft it would operate as follows: if it became the custom for everyone to take whatever he wanted, private property and theft would simultaneously cease to exist. So also suicide is immoral, since if it became general the human race would cease to exist. Kant, however, was looking at only one side of the problem. Moral conduct is frequently limited to an individual, and cannot be generalised for all humanity. Thus, for instance, if one about to sacrifice his life for the good of his fellows were to estimate his action according to Kant’s formula, he would reach a conclusion similar to that in the case of suicide; if everyone were to sacrifice his life for others, no one would remain alive, and so, according to Kant, the sacrifice of one’s life for the good of others would be an immoral act. It is plain that in his search for a rational basis of morality, Kant found only a hollow form, void of any substantial body of morality. It is not enough that a moral man should take his consciousness of duty as a guide. He must know what would be the result of his acts. If it is immoral to make a false promise, it is because people would lose confidence in such promises, and confidence is necessary to our well-being. When the formula of Kant condemns theft, it is because, if theft became general, there could be no private property, and property is regarded as necessary to the well-being of men. Suicide is immoral, according to Kant, because it would lead to the disappearance of the human race, and human life is of course a good. Kant tried to found his theory of morality on a rational basis which excluded the idea of the general good, but it was impossible for him to avoid it. His “practical reason,” when it raised the consciousness of duty to a principle, should have pointed the goal towards which moral acts were to be directed. In this matter, I find that Kant’s ideas are very vague, although extremely interesting.