It has long been recognized that sections of the fragments identified as from Aristoxenus’ Pythagorean Precepts by Stobaeus are preserved, sometimes word for word and sometimes with minor changes, in Iamblichus’ On the Pythagorean Way of Life. Iamblichus gives no indication that he is drawing on the Precepts in these cases, but Iamblichus’ general procedure in all of his works is not to identify explicitly the sources on which he is drawing. A clear example is the first sentence of fragment 2, which is derived from Stobaeus and which is repeated word for word but without attribution in section 175 of Iamblichus’ On the Pythagorean Way of Life.