whether there is, in fact, a social physiology. Investigation in the ordinary sciences was facilitated by the discovery, which was early made, that its objects grouped themselves in classes, of which each individual corresponded with a common type, and that what was observed of one could be predicated of all of its class. Were social phenomena susceptible of a similar generalization?
The question has only recently been answered with clear knowledge; but hints of the solution were given two or three hundred years ago to one or two favored thinkers. Giambattista Vico made the first approach to it toward the close of the seventeenth century, in his "Scienza nuova." Johann Peter Süssmilch gained another glimpse of it a hundred years afterward. Half a century after him. Herder advanced the doctrine that a plan ruled in social development, the discovery of which must be sought through the study of the philosophy of history. The application of mathematical calculations to human events is due to two astronomers. Laplace, investigating the law of probabilities, suggested that the methods of observation and calculation might be of service in social and intellectual studies. The second astronomer, Quetelet, was the real founder of social physiology. Since his investigations there has been no doubt of the practicability of studying, by the methods of natural research, those social phenomena which had previously been only looked at through the telescope of speculation; for he, not contented with mere suggestions, made actual analyses of civil society; instituted mathematical investigations with groups of vital phenomena, to which only a few before him had ventured to apply the measuring-rod; showed the regularity of the formation of the social body and of its vital manifestations; and made apparent the close relations of cause and effect in the apparently voluntary acts of men in society. The followers on Quetelet's lines during the last thirty years have been very numerous. A whole school have adopted exactly his spirit and methods; others have worked analytically; and others have endeavored to build up a metaphysical sociology. The literature of many nations, particularly of England, Germany, France, and Italy, has now a legion of works aiming to investigate the phenomena of social life from the most diversified points of view, tenable and untenable; they differ widely in character, but all agree that the laws of human social phenomena are a legitimate subject of study. The mathematical method has been vastly aided during the same period by the operations of the statistical bureaus that have been established in most civilized countries, in collecting and classifying facts, which, with the averages they afford, are to the social philosopher what his chemicals, microscopes and instruments of precision, and his experiments, are to the natural philosopher.
The great progress which has been made in the comprehension of the principles of social philosophy is due to the method which has been adopted of laying aside for a time the consideration of single