Hence the Pythagoreans in their theology called it sometimes "universe," sometimes "heaven," sometimes "all," sometimes "Fate" and "eternity," "power" and "trust" and "Necessity," "Atlas" and "unwearying," and simply "God" and "Phanes" and "sun."They called it "universe," because all things are arranged by it both in general and in particular, and because it is the most perfect boundary of number, in the sense that "decad" is, as it were, "receptacle," just as heaven is the receptacle of all things, they called it "heaven" and, among the Muses, "Ourania."