Though a distinct consciousness of causation is the last trait which intellectual progress brings -- though with the savage a simple mechanical cause is not conceived as such -- though even among the Greeks the flight of a spear was thought of as guided by a god -- though from their times down almost to our own, epidemics have been habitually regarded as of supernatural origin -- and though among social phenomena, the most complex of all, causal relations may be expected to continue longest unrecognized; yet in our days, the existence of such causal relations has become clear enough to force on all who think, the inference that before meddling with them they should be diligently studied. The mere facts, now familiar, that there is a connexion between the numbers of births, deaths, and marriages, and the price of corn, and that in the same society during the same generation, the ratio of crime to population varies within narrow limits, should be sufficient to make all see that human desires, using as guide such intellect as is joined with them, act with approximate uniformity. It should be inferred that among social causes, those initiated by legislation, similarly operating with an average regularity, must not only change men's actions, but, by consequence, change their natures probably in ways not intended. There should be recognition of the fact that social causation, more than all other causation, is a fructifying causation; and it should be seen that indirect and remote effects are no less inevitable than proximate effects. I do not mean that there is denial of these statements and inferences. But there are beliefs and beliefs -- some which are held nominally, some which influence conduct in small degrees, some which sway it irresistibly under all circumstances; and unhappily the beliefs of lawmakers respecting causation in social affairs, are of the superficial sort. Let us look at some of the truths which all tacitly admit, but which scarcely any take deliberate account of in legislation.
There is the indisputable fact that each human being is in a certain degree modifiable both physically and mentally. Every theory of education, every discipline, from that of the arithmetician to that of the prize-fighter, every proposed reward for virtue or punishment for vice, implies the belief, embodied in sundry proverbs, that the use or disuse of each faculty, bodily or mental, is followed by an adaptive change in it -- loss of power or gain of power, according to demand.
There is the fact, also in its broader manifestations universally recognized, that modifications of Nature in one way or other produced, are inheritable. No one denies that by the accumulation of small changes, generation after generation, constitution fits itself to conditions; so that a climate which is fatal to other races is innocuous to the adapted race. No one denies that peoples who belong to the same original stock but have spread into different habitats where they have led different lives, have acquired in course of time different aptitudes and different tendencies. No one denies that under new conditions new national characters are even now being moulded; as witness the Americans. And if no one denies a process of adaptation everywhere and always going on, it is a manifest implication that adaptive modifications must be set up by every change of social conditions.
To which there comes the undeniable corollary that every law which serves to alter men's modes of action -- compelling, or restraining, or aiding, in new ways -- so affects them as to cause in course of time adjustments of their natures. Beyond any mediate effect wrought, there is the remote effect, wholly ignored by most a re-moulding of the average character: a re-moulding which may be of a desirable kind or of an undesirable kind, but which in any case is the most important of the results to be considered.
Other general truths which the citizen, and still more the legislator, ought to contemplate until they become wrought into his intellectual fabric, are disclosed when we ask how social activities are produced; and when we recognize the obvious answer that they are the aggregate results of the desires of individuals who are severally seeking satisfactions, and ordinarily pursuing the ways which, with their pre-existing habits and thoughts, seem the easiest -- following the lines of least resistance: the truths of political economy being so many sequences. It needs no proving that social structures and social actions must in some way or other be the outcome of human emotions guided by ideas --either those of ancestors or those of living men. And that the right interpretation of social phenomena is to be found in the co-operation of these factors from generation to generation, follows inevitably.
