The same objection is sometimes put into another form. It is said that laws of chemistry, for example, are general statements about what happens when bodies are treated in a certain way, and that such laws are fit matter for science; but that moral laws are different, because they tell us to do certain things, and we may or may not obey them. The mood of the one is indicative, of the other imperative. Now it is quite true that the word law in the expression 'law of nature,' and in the expressions 'law of morals,' 'law of the land,' has two totally different meanings, which no educated person will confound; and I am not aware that any one has rested the claim of science to judge moral questions on what is no better than a stale and unprofitable pun. But two different things may be equally matters of scientific investigation, even when their names are alike in sound. A telegraph post is not the same thing as a post in the War Office, and yet the same intelligence may be used to investigate the conditions of the one and the other. That such and such things are right or wrong, that such and such laws are laws of morals or laws of the land, these are facts, just as the laws of chemistry are facts; and all facts belong to science, and are her portion forever. Again, it is sometimes said that moral questions have been authoritatively settled by other methods; that we ought to accept this decision, and not to question it by any method of scientific inquiry; and that reason should give way to revelation on such matters. I hope before I have done to show just cause why we should pronounce on such teaching as this no light sentence of moral condemnation: first, because it is our duty to form those beliefs which are to guide our actions by the two scientific modes of inference, and by these alone; and, secondly, because the proposed mode of settling ethical questions by authority is contrary to the very nature of right and wrong. Leaving this, then, for the present, I pass on to the most formidable objection that has been made to a scientific treatment of ethics. The objection is that the scientific method is not applicable to human action, because the rule of uniformity does not hold good. Whenever a man exercises his will, and makes a voluntary choice of one out of various possible courses, an event occurs whose relation to contiguous events cannot be included in a general statement applicable to all similar cases. There is something wholly capricious and disorderly, belonging to that moment only; and we have no right to conclude that if the circumstances were exactly repeated, and the man himself absolutely unaltered, he would choose the same course.