Use when onboarding into a fragmented industry, auditing a body of research, or designing a curriculum that needs to show *why* rival schools talk past each other. ---

All Greek philosophy splits into two family trees—the Ionian line from Thales and the Italian line from Pherecydes and Pythagoras—and operates across three functional domains: Physics (the world), Ethics (human conduct), and Dialectics (the governing logic of both). Diogenes constructs his entire ten-book architecture on the Hellenistic genre of *Diadochai* (Successions), pioneered by Sotion and Hippobotus. Instead of organizing ideas by abstract topic, he maps intellectual history as a bifurcation of two genealogical trunks: the **Ionian** (empirical, cosmological, shifting into civic ethics via Socrates, and branching into the Academy, Lyceum, and Stoa) and the **Italian** (mythic-mathematical, beginning with Pherecydes and Pythagoras, passing through Eleatic logic into Atomism and Epicurus). Across this dual genealogy, Diogenes overlays a triadic functional division—Physics, Ethics, and Dialectics—which represents a historical sequence of dominance: early natural inquiry (*physis*) ruled until Archelaus; Socrates pivoted the system toward human conduct (*ethos*); and Zeno of Elea weaponized the testing of arguments (*dialektike*). A school (*hairesis*) is only legible when you know both its bloodline (Succession) and which of the three engines it privileges. **[INTERPRETATION: PRISCA THEOLOGIA / ESOTERIC]** In the esoteric reception of the Renaissance, Diogenes's two-trunk map was read as the split between the **Exoteric/Physical** path (the Ionian observation of nature's outer shell) and the **Esoteric/Mathematical-Theurgic** path (the Italian school of Pherecydes and Pythagoras, which works through number, soul-transmigration, and divine names). For readers in the Ficinian chain, the crucial synthesis occurs when Plato—an Ionian-line heir of Socrates—travels to Italy to absorb the Pythagorean lineage, welding the two trunks back together into a single sacred philosophy. The triad of Physics, Ethics, and Dialectics was similarly mapped onto the three stages of the soul's purification: Ethics cleanses the unruly passions, Physics contemplates the divine order in the visible cosmos, and Dialectics (understood in the Platonic sense as the ascent to First Principles) elevates the intellect to the intelligible realm.