Diogenes Laërtius · fl. 3rd century CE
Lives of Eminent Philosophers 7.79 — Diogenes Laërtius on the Stoics
Translation by R. D. Hicks (1925)
Diogenes Laërtius, Lives of Eminent Philosophers 7.79
Reported speech · Diogenes Laërtius on the Stoics
Further, arguments may be divided into true and false. The former draw their conclusions by means of true premisses; e.g. “If virtue does good, vice does harm; but virtue does good, therefore vice does harm.” Those are false which have error in the premisses or are inconclusive; e.g. “If it is day, it is light; but it is day, therefore Dion is alive.” Arguments may also be divided into possible and impossible, necessary and not necessary. Further, there are statements which are indemonstrable because they do not need demonstration; they are employed in the construction of every argument. As to the number of these, authorities differ; Chrysippus makes them five. These are assumed alike in reasoning specifically conclusive and in syllogisms both categorical and hypothetical.
Cite this passage
Diogenes Laërtius, Lives of Eminent Philosophers 7.79 (on the Stoics), tr. R. D. Hicks (1925)
https://whatwouldstoicsdo.com/passage/lives-of-the-stoics/7.79
Diogenes Laërtius, Lives of Eminent Philosophers, Book VII, tr. R. D. Hicks (Loeb, 1925). Text: Perseus Digital Library (CC BY-SA 4.0). Sources and licences
In plain English
AI-written notesDivides arguments into true and false and into possible and impossible kinds, and introduces the indemonstrable statements, basic reasoning steps that need no proof and feed all arguments. Chrysippus counts five of them. Logic terminology.
Older wording
- “indemonstrable”
- — basic and unprovable because they need no proof
- “categorical”
- — stating something directly, without an if
- “premisses”
- — the statements an argument starts from
Themes and situations
- Judgements and impressions
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