"The first definition of number is attributed to Thales, who defined it as a collection of units... following the Egyptian view. The Pythagoreans 'made number out of one' [Aristotle, Metaph. A. 5, 986 a 20]; some of them called it 'a progression of multitude beginning from a unit and a regression ending in it' [, p. 18. 3-5]. Stobaeus credits Modoratus, a Neo-Pythagorean of the time of Nero, with this definition.) Eudoxus defined number as a 'determinate multitude'... has yet another definition, 'a flow of quantity made up of units'... Aristotle gives a number of definitions equivalent to one or other of those just mentioned, 'limited multitude', 'multitude (or combination) of units', 'multitude of indivisibles', 'several ones'... 'multitude measurable by one', 'multitude measured', and 'multitude of measures' (the measure being the unit)."