One Stoic response to the skeptical indistinguishability argument is that it fails to account for expertise: the Stoics allow that while two similar objects create indistinguishable appearances in the amateur, this is not true of the expert, whose appearances succeed in discriminating the pair. This paper re-examines the motivations for this Stoic response, and argues that it reveals the Stoic claim that, in generating a kataleptic appearance, the perceiver’s mind is active, insofar as it applies concepts matching the perceptual stimulus. (...) I argue that this claim is reflected in the Stoic definition of the kataleptic appearance, and that it respects their more general account of mental representation. I further suggest that, in attributing some activity to the mind in creating each kataleptic appearance, and in claiming that the expert’s mind allows her to form more kataleptic appearances than the amateur, the Stoics draw inspiration from the wax tablet model in Plato’s Theaetetus (190e–196d), where Socrates distinguishes the wise from the ignorant on the basis of how well they match sensory input with its appropriate mental ‘seal’ (σφραγίς). (shrink)

The purpose of this paper is to identify the upholders of the thesis reported by Plutarch, De Stoicorum repugnantiis 23, aimed to reject Stoic determinism. A brief introduction will be devoted to the relationship between this text and the more general context of the Stoic philosophy. Then, I will take into account the objection against Stoic determinism raised by some anonymous philosophers: according to it, causal determinism would be inconsistent with the choice among indistinguishables. Chrysippus replied that if that choice (...) were not determined, it would occur without causes; and this would be absurd. Then I will summarize the most likely hypotheses about the identification of Chrysippus’ opponents, and I will opt for Academics. Finally, I will try to conjecture the link between Plutarch’s passage and the debate among Stoics and Academics about indistinguishables, as we know it from other sources. (shrink)