26 PEOTECTION OE FEEE TEADE.
land has grown in wealth since the abolition of protection proves no more for free trade than the growth of the United States under a protective tariff does for protection. It does not follow that an institution is good because a country has "prospered under it, nor bad because a country in which it exists is not prosperous. It does not even follow that institutions to be found in all prosperous countries and not to be found in backward countries are therefore beneficial. For this, at various times, might have been confidently asserted of slavery, of polygamy, of aristocracy, of established churches, and it may still be asserted of public debts, of private property in land, of pauperism, or of the existence of distinctively vicious or criminal classes. JSTor even when it can be shown that certain changes in the prosperity of a country, of an industry, or of a class, have followed certain other changes in laws or institutions can it be inferred that the two are related to each other as effect and cause, unless it can also be shown that the assigned cause tends to produce the assigned effect, or unless, what is clearly impossible in most cases, it can be shown that there is no other cause to which the effect can be attributed. The almost endless multiplicity of causes constantly operating in hurgan societies, and the almost endless interference of effect with effect, make that popular mode of reasoning which logicians call the method of simple enumeration worse than useless in social investigations.
As for reliance upon statistics, that involves the additional difficulty of knowing whether we have the right statistics. Though " figures cannot lie," there is 4 in their collection and grouping such liability to oversight and such temptation to bias that they are to be