Some years ago I used to know an ardent single tax propagandist who found my way of arguing intensely irritating, because, as he phrased it, I had "no principles." We would be discussing, for example, a protective tariff, and I would wish to collect statistics, but discovered to my bewilderment that to my single tax friend a customs duty was "stealing" on the part of the government. The government had a right to tax land, because that was the gift of nature, but it had no right to tax the products of human labor, and when it took a portion of the goods which anyone brought into a country, the government was playing the part of a robber. Of course such a man was annoyed by the suggestion that in the early stages of a country's development it might possibly be a good thing for the country to make itself independent and self-sufficient by encouraging the development of its manufactures; that, on the other hand, when these manufactures had grown to such a size that they controlled the government, it might be an excellent thing for the country to subject them to the pressure of foreign competition, in order to lower their value as a preliminary to socializing them. The reader who comes to this book looking for hard and fast rules of life will be disappointed. It would be convenient if someone could lay down for us a moral code, and lift from our shoulders the inconvenient responsibility of deciding about our own lives. There may be persons so weak that they have to have the conditions of their lives thus determined for them; but I am not writing for such persons. I am writing for adult and responsible individuals, and I bear in mind that every individual is a separate problem, with separate needs and separate duties. There are, of course, a good many rules that apply to everybody in almost all emergencies, but I cannot think of a single rule that I would be willing to say I would apply in my life without a single exception. "Thou shalt not kill" is a rule that I have followed, so far without exception; but as soon as I turn my imagination loose, I can think of many circumstances under which I should kill. I remember discussing the matter with a pacifist friend of mine, an out-and-out religious non-resistant. I pointed out to him that people sometimes went insane, and in that condition they sometimes seized hatchets and killed anyone in sight. What would my pacifist friend do if he saw a maniac attacking his children with a hatchet? It did not help him to say that he would use all possible means short of killing the maniac; he had finally to admit that if he were quite sure it was a question of the life of the maniac or the life of his child, he would kill. And this is not mere verbal quibbling, because such things do happen in the world, and people are confronted with such emergencies, and they have to decide, and no rule is a general rule if it has a single exception. There is a saying that "the exception proves the rule," but this is very