A. C. Lloyd : "Emotion and Decision in Stoic Psychology" In
John M. Rist (ed.): The Stoics

"The Stoa gave a place to images earlier in the epistemic process: they were to be involved in sense perception itself. Moreover, neither process could proceed from a mere "judgment" to belief or to action without an act of assent. (This is familiar from Augustine to Descartes and Malebranche, none of whom learned it from Plato or Aristotle.) Stoics were willing to treat images themselves as objects of assent, so that the distinction of image (representation) and judgment tended to dissolve."