they were able to communicate. Of this remark a melancholy illustration occurs (as M. Turgot long ago predicted) in the case of the French economists; and many examples of a similar import might be produced from the history of science in our country; more particularly from the history of the various medical and metaphysical schools which successively rose and fell during the last century.
With the circumstances already suggested, as conspiring to accelerate the progress of knowledge, another has co-operated very extensively and powerfully; the rise of the lower orders in the different countries of Europe,—in consequence partly of the enlargement of commerce, and partly of the efforts of the Sovereigns to reduce the overgrown power of the feudal aristocracy.
Without this emancipation of the lower orders, and the gradual diffusion of wealth by which it was accompanied, the advantages derived from the invention of printing would have been extremely limited. A certain degree of ease and independence is essentially requisite to inspire men with the desire of knowledge, and to afford the leisure necessary for acquiring it; and it is only by the encouragement which such a state of society presents to industry and ambition, that the selfish passions of the multitude can be interested in the intellectual improvement of their children. It is only, too, in such a state of society, that education and books are likely to increase the sum of human happiness; for while these advantages are confined to one privileged description of individuals, they but furnish them with an additional engine for debasing and misleading the minds of their inferiors. To all which it may be added, that it is chiefly by the shock and collision of different and opposite prejudices, that truths are gradually cleared from that admixture of error which they have so strong a tendency to acquire, wherever the course of public opinion is forcibly constrained and guided within certain artificial channels, marked out by the narrow views of human policy. The diffusion of knowledge, therefore, occasioned by the rise of the lower orders, would necessarily contribute to the improvement of useful