All the political changes of the age promote it, since they all tend to raise the low and to lower the high. Every extension of education promotes it, because education brings people under common influences, and gives them access to the general stock of facts and sentiments. Improvements in the means of communication promote it, by bringing the inhabitants of distant places into personal contact, and keeping up a rapid flow of changes of residence between one place and another. The increase of commerce and manufactures promotes it, by diffusing more widely the advantages of easy circumstances, and opening all objects of ambition, even the highest, to general competition, whereby the desire of rising becomes no longer the character of a particular class, but of all classes. A more powerful agency than even all these, in bringing about a general similarity among mankind, is the complete establishment, in this and other free countries, of the ascendency of public opinion in the State.