Little by little his conversation, always instructive and animated, gave a special direction to my tastes, which would have led me by preference towa… - Adolphe Quetelet

It may be seen, in my work, that the course which I have adopted is that followed by the natural philosopher, in order to grasp the laws that regulate the material world. By the seizure of facts, I seek to rise to an appreciation of the causes whence they spring.

In every instance, it is not my method that is defective; proper observations alone fail me. But will it be ever impossible to have them perfectly precise? I believe that even at present we have them sufficiently so to enter, at least, on the great problem under consideration. Name them as you will, the actions which society stamps as crimes, and of which it punishes the authors, are reproduced every year, in almost exactly the same numbers; examined more closely, they are found to divide themselves into almost exactly the same categories; and, if their number were sufficiently large, we might carry farther our distinctions and subdivisions, and should always find there the same regularity. It will then remain correct to say, that a given species of actions is more common at one given age than at any other given age.

The progressive development of moral and intellectual man has scarcely occupied their [scientists] attention; nor have they noted how the faculties of his mind are at every age influenced by those of the body, nor how his faculties mutually react.