Full Idea
Knowledge itself, say the stoics, is either a secure grasp or a disposition in the reception of presentations not reversible by argument.
Gist of Idea
Knowledge is a secure grasp of presentations which cannot be reversed by argument
Source
report of Stoic school (fragments/reports [c.200 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.47
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.12
A Reaction
Helpful, but not enough. Fools hold secure grasps which cannot be refuted, as far as they are concerned. Consensus needed. Falsification? The truth-bearer is a 'presentation' (an appearance), which is different from modern accounts.