Waerden 1961 , p. 43. ^ Iamblichus , Life of Pythagoras ,(trans. e.g. Guthrie 1987 ) cited in van der Waerden 1961 , p. 108. See also Porphyry , Life of Pythagoras , paragraph 6, in Guthrie 1987 Van der Waerden ( van der Waerden 1961 , pp. 87-90) sustains the view that Thales