Adolphe Quetelet

"The influence of Quetelets ideas spread throughout the sciences, even to the physical sciences. The two primary founders of the modern kinetic theory of gases, based on considerations of probability, were James Clerk Maxwell and Ludwig Boltzmann. Both acknowledged their debt to Quetelet. ...historians generally consider the influence of the natural sciences on the social sciences, whereas in the case of Maxwell and Boltzmann, there is an influence of the social sciences on the natural sciences, as Theodore Porter has shown."

"Maxwell... mastered electricity and magnetism, light and heat, pretty much mopping up all the major areas of physics beyond those that Newton had... taken care of—gravitation and the laws of motion. ...Maxwell detected an essential shortcoming in Newtons laws of motion, too. They worked... for macroscopic objects, like cannonballs and rocks. But what about the submicroscopic molecules from which such objects were made? ...Newtons laws ...did you no good because you could not possibly trace the motion of an individual molecule ...Maxwell applied the sort of statistical thinking that Quetelet had promoted."

"Maxwell probably first encountered Quetelet in an article by... John Herschel... (...familiar with Quetelet as a fellow astronomer). Later, in 1857, Maxwell read a newly published book by... Henry Thomas Buckle. Buckle, himself clearly influenced by Quetelet, believed that science could discover the "laws of the human mind" and that human actions are a part of "one vast system of universal order." ...Though Maxwell found Buckles book "bumptious," he recognized it as a source of original ideas, and the statistical reasoning Buckle applied to society seemed just the thing... needed to deal with molecular motion."

"Little by little his conversation, always instructive and animated, gave a special direction to my tastes, which would have led me by preference towards letters. I resolved to complete my scientific studies and followed the courses in advanced mathematics given by M. [Jean Guillaume] Gamier. It was at the same time agreed by us that, in order to relieve him in his work, I should give some of the other courses with which he was charged. I thus found myself his pupil and his colleague."

"I have always comprehended with difficulty... how persons pre-occupied doubtless by ideas, have seen any tendency to materialism in exposition of a series of facts deduced from documents. In giving to my work the title of Physics, I have had no other aim than to collect, in uniform order, the phenomena affecting man, nearly as physical science brings together the phenomena appertaining to the material world. If certain facts present themselves with an alarming regularity, to whom is blame to be ascribed? Ought charges of materialism to be brought against him who points out that regularity?"

"Limits... seem to me of two kinds, ordinary or natural, and extraordinary or beyond the natural. The first limits comprise within them the qualities which deviate more or less from the mean, without attracting attention by excess on one side or the other. When the deviations become greater, they constitute the extraordinary class, having itself its limits, on the outer verge of which are things preternatural... We must conceive the same distinctions in the moral world."

"Hitherto, the science of Man has been limited to researches... respecting some of its laws, to results deduced from single or insulated observations, and to theories often based on mere glimpses; and these constitute pretty nearly all the materials it possesses."

"The most important of Quetelets statistical principles... include the conception of the Average Man as a type, the significance for social science of the regularities found in the moral actions of man, and the theoretical basis of the distribution of group phenomena about their type."

"Quetelet published quite a number of poems, and until the age of thirty he continued to exercise his poetical talents as pastime and relief from his scientific studies. His poems were of a serious tone, but were well received by both public and critics. We may mention here an Essai sur la romance, which Quetelet brought out in 1823. ...This essay, together with translations, in prose and in verse, of German, English, Italian, and Spanish romances, shows Quetelets wide acquaintance at that early age with the various European literatures."

"It has seemed to me that the theory (calcul) of probabilities ought to serve as the basis for the study of all the sciences, and particularly of the sciences of observation."

"The great body of population dynamics, like those of the motion of the celestial bodies, can be solved—and what is most remarkable, there is a surprising analogy between the formulas employed in these calculations. I believe that I have achieved to some extent what I have long said about the possibility of founding a social mechanics on the model established by celestial mechanics—to formulate the motions of the social body in accordance with those of celestial bodies, and to find there again the same properties and laws of conservation."

"The more advanced the sciences have become, the more they have tended to enter the domain of mathematics, which is a sort of center towards which they converge. We can judge of the perfection to which a science has come by the facility, more or less great, with which it may be approached by calculation."