SVF I.85

Original — Ancient Greek

δοκεῖ δ' αὐτοῖς ἀρχὰς εἶναι τῶν ὅλων δύο, τὸ ποιοῦν καὶ τὸ πάσχον. τὸ μὲν οὖν πάσχον εἶναι τὴν ἄποιον οὐσίαν τὴν ὕλην, τὸ δὲ ποιοῦν τὸν ἐν αὐτῇ λόγον τὸν θεόν. τοῦτον γὰρ ἀίδιον ὄντα διὰ πάσης αὐτῆς δημιουργεῖν ἕκαστα. τίθησι δὲ τὸ δόγμα τοῦτο Ζήνων ὁ Κιτιεὺς ἐν τῷ περὶ οὐσίας.

StoicOs Translation

In their view there are two principles of all things: that which acts and that which is acted upon. That which is acted upon is unqualified substance, matter; that which acts is the reason (logos) within it, god. For this, being eternal, crafts each thing throughout the whole of matter. Zeno of Citium lays down this doctrine in his On Substance.

Context

Diogenes Laërtius, compiling around five centuries after Zeno, opens his survey of Stoic physics with this summary. The opening “in their view” describes the Stoics as a school; only the final sentence anchors the doctrine to Zeno personally — and names his lost treatise On Substance (Περὶ οὐσίας) as its source.

Source notes:Greek text verified against H. von Arnim, SVF I (1903), no. 85, p. 24 (scanned page). Under the same number von Arnim prints further reports: Aëtius I 3,25 („Ζήνων Μνασέου Κιτιεὺς ἀρχὰς μὲν τὸν θεὸν καὶ τὴν ὕλην…“) and Achilles Tatius p. 124E. The doctrine is thus multiply attested, though these reports may draw on a shared doxographic tradition.

What the source actually tells us

This is a testimonium in Diogenes' own words, not a quotation from Zeno's book. What it secures is the two-principle doctrine — passive unqualified matter and the active logos-god within it — and Diogenes' explicit statement that Zeno laid this down in his On Substance. The doctrine is multiply attested (Aëtius and Achilles Tatius report it too), though the parallel reports may derive from a shared doxographic tradition rather than from independent reading of Zeno.

Philosophical meaning

This is the bedrock of Stoic physics: one world, two aspects. Matter by itself has no qualities; everything it becomes, it becomes through the active reason — god — working within it, not upon it from outside. There is no transcendent creator standing apart from the world: god is the craftsman-reason immanent in all matter. From this follow the Stoic doctrines of providence, fate and the rational cosmos.

Scholarly uncertainty

The wording is Diogenes', and in the continuation of DL 7.134 the manuscript tradition contains a well-known crux (whether the principles are called bodies or incorporeal — σώματα/ἀσωμάτους); von Arnim's excerpt for no. 85 stops before that sentence. The parallel reports in Aëtius and Achilles Tatius formulate the doctrine slightly differently (god and matter as the two principles).

Go deeper

• Study the principles in Stoic Physics →
• Amor fati, honestly explained →