=Formal Character of Such Reason.=--This extreme separation of reason from experience brings with it, however, a serious problem. We shall first state this problem; and then show that its artificial and insoluble character serves as a refutation of Kant's theory of a transcendental, or wholly non-natural and non-empirical, mode of knowledge. Reason which is wholly independent of experience of desires and their results is, as Kant expressly declares, purely _formal_. (Abbott's _Kant_, p. 33; p. 114.) That is to say, it is _empty_; it does not point out or indicate anything particular to be done. It cannot say be industrious, or prudent, generous; give, or refrain from giving, so much money to this particular man at this particular time under just these circumstances. All it says is that morality is rational and requires man to follow the law of reason. But the law of reason is just that a man should follow the law of reason. And to the inevitable inquiry "What then is the law of reason?" the answer still is: To follow the law of reason. How do we break out of this empty circle into specific knowledge of the specific right things to be done? Kant has an answer, which we shall now consider. =Kant's Method.=--He proceeds as follows: The law is indeed purely formal or empty (since, once more, all specific ends are "empirical" and changeable), but it is so because it is universal. Now nothing which is universal can contradict itself. All we need to do is to take any proposed principle of any act and ask ourselves whether it can be universalized without self-inconsistency. If it cannot be, the act is wrong. If it can be, the act is right. For example: "May I, when in distress, make a promise with the intention not to keep it?... The shortest way, and an unerring one to discover the answer to the question whether a lying promise is consistent with duty, is to ask myself, Should I be content that my maxim (to extricate myself from trouble by a false promise) should hold good as a universal law, for myself as well as for others? And should I be able to say to myself, every one may make a deceitful promise when he finds himself in a difficulty from which he cannot otherwise extricate himself? Then I personally become aware that while I can will the lie, I can by no means will that lying should be a universal law. For with such a law there would be no such thing as a promise. No one should have any faith in the proffered intention, or, if they do so over hastily, would pay one back in one's own coin at the first opportunity" (_Op. cit._, p. 19). The principle if made universal simply contradicts itself, and thus reveals that it is no principle at all, not rational. Summing this up in a formula, we get as our standard of right action the principle: "Act as if the maxim of thy action were to become by thy will a universal law of nature" (_Op. cit._, p. 39).