Full Idea
One cannot say that the soul grasps the externally existing objects by means of the states of the senses on the basis of the similarity of these states to the externally existing objects. For on what basis will it know the similarity?
Gist of Idea
How could you ever know that the presentation is similar to the object?
Source
comment on Chrysippus (fragments/reports [c.240 BCE]) by Sextus Empiricus - Outlines of Pyrrhonism 2.74
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.26
A Reaction
This exactly the main modern reason for rejecting the correspondence theory of truth. You are welcome to affirm a robust view of truth, but supporting it by claiming a correspondence or resemblance is dubious.
Related Idea
Idea 20780 Graspable presentations are criteria of facts, and are molded according to their objects [Chrysippus, by Diog. Laertius]