Some material from "The World" was revised for publication as "Principia philosophiae" or "Principles of Philosophy" (1644), a Latin textbook at first intended by Descartes to replace the Aristotelian textbooks then used in universities. In the "Principles" the heliocentric tone was softened slightly with a relativist frame of reference. The last chapter of "The World" was published separately as "De Homine" ("On Man") in 1662. The rest of "The World" was finally published in 1664, and the entire text in 1677.