Since then the rate of progress has been accelerated, and this has been due to several causes. The expansion of sea commerce has produced more wealth, and wealth means greater leisure, and more writers and readers. In the second place, mathematics and physics are more studied in colleges, and their tendency is to liberate us from subjection to the authority of the ancients. Again, the foundation of scientific Academies has given facilities both for communicating and for correcting new discoveries; the art of printing provides a means for diffusing them; and, finally, the habit of writing in the vulgar tongue makes them accessible. The author might also have referred to the modern efforts to popularise science, in which his friend Fontenelle had been one of the leaders. He proceeds, in this connection, to lay down a rather doubtful principle, that in any two countries the difference in enlightenment between the lowest classes will correspond to the difference between the most highly educated classes. At present, he says, Paris and London are the places where human wisdom has reached the most advanced stage. It is certain that the ten best men of the highest class at Ispahan or Constantinople will be inferior in their knowledge of politics and ethics to the ten most distinguished sages of Paris or London. And this will be true in all classes. The thirty most intelligent children of the age of fourteen at Paris will be more enlightened than the thirty most intelligent children of the same age at Constantinople, and the same proportional difference will be true of the lowest classes of the two cities. But while the progress of speculative reason has been rapid, practical reason--the distinction is the Abbe's--has made little advance. In point of morals and general happiness the world is apparently much the same as ever. Our mediocre savants know twenty times as much as Socrates and Confucius, but our most virtuous men are not more virtuous than they. The growth of science has added much to the arts and conveniences of life, and to the sum of pleasures, and will add more. The progress in physical science is part of the progress of the "universal human reason," whose aim is the augmentation of our happiness. But there are two other sciences which are much more important for the promotion of happiness--Ethics and Politics--and these, neglected by men of genius, have made little way in the course of two thousand years. It is a grave misfortune that Descartes and Newton did not devote themselves to perfecting these sciences, so incomparably more useful for mankind than those in which they made their great discoveries. They fell into a prevailing error as to the comparative values of the various domains of knowledge, an error to which we must also ascribe the fact that while Academies of Sciences and Belles-Lettres exist there are no such institutions for Politics or Ethics.