Pythagorean astronomical system
An astronomical system positing that the Earth, Moon, Sun, and planets revolve around an unseen "Central Fire" was developed in the fifth century BC and has been attributed to the Pythagorean philosop
Pythagoreanism
Pythagoreanism originated in the 6th century BC, based on and around the teachings and beliefs held by Pythagoras and his followers, the Pythagoreans. Pythagoras established the first Pythagorean comm
Tetractys
The tetractys (Greek: τετρακτύς), or tetrad, or the tetractys of the decad is a triangular figure consisting of ten points arranged in four rows: one, two, three, and four points in each row, which is
Monad (philosophy)
The term monad (from Ancient Greek μονάς (monas) 'unity', and μόνος (monos) 'alone') is used in some cosmic philosophy and cosmogony to refer to a most basic or original substance. As originally conce