Hitherto, the science of Man has been limited to researches... respecting some of its laws, to results deduced from single or insulated observations,… - Adolphe Quetelet

Artists have, for the most part, bound themselves down to follow a blind routine. Noble exceptions, however, have presented themselves. Nicholas Poussin, one of the most profound thinkers, whom the arts have produced, took care to correct and regulate by the antique the proportions which Leon Baptista Alberti and Albert Durer had given from the living model.

It is only by long and laborious study, and by the comparison of a number of individuals, that it will be possible to succeed in establishing correct average proportions each age, and in settling the limits betwixt they can be made to vary, without ceasing to be accurate and faithful to nature—our first and guide in this difficult study.

This observation is merely the extension of a law well known to all who have studied the condition of society in a philosophic manner: it is, that so long as the same causes exist, we must expect a repetition of the same effects. What has induced some to believe that moral phenomena did not obey this law, has been the too great influence ascribed all times to man himself over his actions.