Fragments and Testimonia (Diels/Kranz)

Because Pythagoras, by the earliest testimony, wrote nothing. Diels himself recognized that the Pythagorean material did not fit his standard A (testimonia) and B (fragments) division, and he resorted to a more elaborate classification for this section . What the Diels/Kranz chapter on Pythagoras contains is overwhelmingly testimonia: later reports about his life, his travels, his teachings, and the organization of his school. The ethical precepts and symbolic sayings collected there are attributed to the early Pythagorean community rather than to a written corpus. This absence of autograph fragments is not an editorial oversight but a historical fact that the edition is designed to make visible, and it remains the single most important constraint on any reconstruction of Pythagoras's own thought.

For most Presocratics, Diels/Kranz presents a relatively clean sequence of testimonia followed by verbatim fragments, with the assumption that the fragments preserve something close to the author's words. For Pythagoras and the Pythagoreans, that model breaks down. The edition must grapple with the fact that Pythagorean doctrine was transmitted orally within a community, that later authors often attributed their own ideas to Pythagoras, and that the boundary between early and late Pythagorean material is contested. The Loeb Early Greek Philosophy edition explicitly notes that Diels abandoned his own A/B division for this material, using a classification from A to E instead . This makes the Pythagorean chapters methodologically different from the rest of the collection, and readers who approach them with the same expectations they bring to Heraclitus or Parmenides will misread what the edition is doing.

Aristotle is the single most important early source for Pythagorean doctrine, and the Diels/Kranz collection preserves his reports extensively. In Metaphysics A5, Aristotle describes the 'so-called Pythagoreans' as thinkers who held that numbers are the principles of all things, and he reports their association of specific numbers with concepts like justice, soul, and opportunity . However, Aristotle's testimony is mediated: he was writing a century and a half after Pythagoras, he relied in part on oral reports from Pythagorean associates like Aristoxenus, and his account is shaped by his own philosophical concerns. A. E. Taylor, in an older but still cited translation of the Metaphysics, judged Aristotle's chapters on the Pythagoreans 'quite inadequate' as an account of their scientific achievements . The Diels/Kranz edition does not resolve this problem but provides the materials for assessing it.

The most significant English-language challenge is Daniel W. Graham's The Texts of Early Greek Philosophy (Cambridge, 2010), which presents a complete bilingual edition of the Presocratics and explicitly presents itself as a replacement for what it calls the 'authoritative but now outdated' Fragmente der Vorsokratiker . Graham includes new fragments and testimonies not in Diels/Kranz and provides a concordance for cross-referencing. The Loeb Classical Library's Early Greek Philosophy, edited by André Laks and Glenn W. Most, also reorganizes the material substantially, as its introduction explains, adopting different classificatory schemes for different authors and acknowledging the arbitrariness of any division . For Pythagoreanism specifically, the 2021 volume Pythagoras redivivus revisits the textual history of texts attributed to Pythagoras and his school, including the transmission of Archytas and Philolaus fragments through Nicomachus and later commentators .

The most common mistake is to treat the testimonia as straightforward evidence for Pythagoras's own views. A report in Iamblichus or Porphyry that 'Pythagoras said X' is not equivalent to a fragment in which Pythagoras says X. The Diels/Kranz numbering system makes this distinction visible if one pays attention to it, but readers often collapse the categories. A related error is to read the ethical precepts and symbolic sayings in the Pythagorean section as a coherent philosophical system, when they are better understood as a layered accretion of community practices, later Platonizing interpretation, and biographical legend. The edition's value lies precisely in allowing the reader to see the seams and gaps in the tradition, rather than smoothing them over into a unified portrait of a sage who never wrote a word.