Both French and Latin are involved with nationalistic and religious implications which could not be entirely shaken off, and so, while they seemed for a long time to have solved the international language problem up to a certain point, they did not really do so in spirit.

English, once accepted as an international language, is no more secure than French has proved to be as the one and only accepted language of diplomacy or as Latin has proved to be as the international language of science.

Comparison of statements made at different periods frequently enable us to give maximal and minimal dates to the appearance of a cultural element or to assign the time limits to a movement of population.

Edward Sapir Quotes