greater part of all the contractual relations between man and man in a civilized community. This will include statutes regulating the practice of medicine, and of law; statutes of patent and copyright; usury laws; Sunday laws; laws regulating the sale of intoxicating liquors at retail; laws regulating the operation of mines; laws against champerty and maintenance; taxation of commerce, and particularly, in this country, of interstate commerce; "drummers'" taxes; laws attempting to regulate dealings in futures, forbidding wager policies on human life, prohibiting the operation of lotteries, and all that large body of legislation by which the regulation of labor is attempted.
When one begins to talk or think about "public policy," by which the economic soundness of all legislation of this sort is to be measured, he is confronted at the outset with the fact that it is a very vague and variable, or, as mathematicians say, a very unassignable quantity. This notion has crystallized itself many times in the law reports. Thus, for example, it has been said by a famous English judge that "public policy does not admit of definition, and is not easily explained,"[1] and by the Supreme Court of the United States that "the application of the rule is more difficult than a clear understanding of it."[2] Again, it was a long time ago well said, in another English case, that public policy "is a very unruly horse, and when once you get astride it you never know where it will carry you,"[3] and, quoting once more, from a recent English case, we find the court saying:
One thing I take to be clear, and it is this—that public policy is a variable quantity; that it must vary and does vary with the habits, capacities and opportunities of the public.[4]
Lord Justice Bowen also to the same effect said very recently in the High Court of Chancery:
The determination of what is contrary to the so-called policy of the law, necessarily varies from time to time. Many transactions are
