On the book of Theophrastos, and on the ‘Lives’ or the ‘Successions of the philosophers,’ as they were often called, the later doxographic writers based their work. Even in Diogenes Laertios there is material from both sources, and we can define some fragments almost in Theophrastos’ own words. In the _Philosophumena_ of Hippolytos the two sources are pretty clearly distinguished: chapters 1-4 and 10 (on Thales, Pythagoras, Empedokles, Herakleitos and Parmenides, see III. English Index under ‘Hippolytos’) are made up of personal anecdotes such as writers of the lives were eager to collect and to repeat; chapters 6-8 and 11 (on Anaximandros, Anaximenes, Anaxagoras, and Xenophanes) come indirectly from the work of Theophrastos. The _Stromateis_ attributed by Eusebios to Plutarch (see III. English Index under ‘Plutarch,’ and _Dox._ pp. 579 f.) are like the last-mentioned chapters of Hippolytos, though the language is often more careless. A comparison of Aetios with Hippolytos, the _Stromateis_, and the doxographic material in Cicero and Censorinus (from Varro) makes it clear that the _Placita_ of Aetios are not based directly on the work of Theophrastos. Indeed (_Dox._ p. 100, and pp. 178 f.) it is evident from an examination of the work of Aetios by itself that much of his material is drawn from Stoic and Epicurean sources. As the main source for what remains after Stoic and Epicurean passages have been cut out, Diels postulates an earlier _Placita_ (_Vetusta placita_, pp. 215 f.). He finds traces of this in the work of Varro as used by Censorinus, in Cicero’s _Tusculan Disputations_, and in some later writers. § 17. Résumé. The doxographic tradition starts with the work of Theophrastos on the opinions of his predecessors. On this work is based immediately the _Vetusta placita_; on the _Vetusta placita_ is based the _Placita_ of Aetios, and there are traces of its use by later writers; the _Placita_ of Aetios may be partially reconstructed from Plutarch’s Placita and Stobaeos’ _Eclogae_. Again, using Theophrastos and gathering anecdotes from every side, writers of the second century B.C. wrote the lives of the philosophers. A line of tradition probably independent of the _Placita_ just considered appears in the work of Hippolytos, who used now the work of Theophrastos, now the lives; in Diogenes Laertios, where material from most various sources is indiscriminately mixed; and in the _Stromateis_ attributed to Plutarch by Eusebios, which are related to the better material of Hippolytos. Simplicius used Theophrastos directly. Finally in the fragments of Philodemos and the related material in Cicero’s _Lucullus_ and _De natura deorum_ we find traces of a use of Theophrastos either by Philodemos himself, or in a common source of both Cicero and Philodemos—probably a Stoic epitome of Theophrastos made by the Phaedros whom Cicero mentions. FOOTNOTES [1] Cf. Herm. _I. G. P._ 10 (_Dox._ 653).