PLATONIC Year, or the Great Year, is a period of time determined by the revolution of the equinoxes, or the space wherein the stars and constellations return to their former places in respect of the equinoxes. The Platonic year, according to Tycho Brahe, is 25,816; according to Ricciolus, 25,910; and according to Cassini, 24,800 years. This period once accomplished, it was an opinion amongst the ancients that the world would begin anew, and the same series of things return in the same order as before.