Astronomers From Belgium

"The most important of Quetelet's 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 Quetelet's wide acquaintance at that early age with the various European literatures."

"As a man of science he was admired; in political affairs he was respected; in private life he was beloved."

"In the history of natural science, Quetelet will, with good right, be placed in the rank of Pascal, Leibnitz, Bernoulli, Laplace, Poisson, and such scientists."

"The mere enumeration of his contributions to pure and mixed mathematics would occupy a very large space, and from their intrinsic merit, patient and conscientious research and earnest regard for truth, would alone have secured him a foremost place among the distinguished and scientific men of the present century."

"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."

"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 Newton's 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? ...Newton's 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 Buckle's 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."

"No other work in the English language contains such an extensive and succinct account of the different branches of physics or exhibits such a general knowledge of the whole field in so small a compass."

"In principle, wrote Quetelet, the courage or criminality of a real person could be established... but it was wholly unnecessary for social physics. Instead, the physicist need only arrange that courageous and criminal acts be recorded throughout society, as the latter already were, and then the average man could be assigned a "penchant for crime" equal to the number of criminal acts committed divided by the population. In this way, a set of discrete acts by distinct individuals was transformed into a continuous magnitude... an attribute of the average man."

"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."

"This great body (the social body) subsists by virtue of conservative principles, as does everything which has proceeded from the hands of the Almighty... When we think we have reached the highest point of the scale we find laws as fixed as those which govern the heavenly bodies: we turn to the phenomena of physics, where the free will of man is entirely effaced, so that the work of the Creator may predominate without hindrance. The collection of these laws, which exist independently of time and of the caprices of man, form a separate science, which I have considered myself entitled to name social physics."

"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."

"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."