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 early Stoics diagnose vicious agents with various psychological diseases, e.g. love of money and love of wine. Such diseases are characterized as false evaluative opinions that lead the agent to form emotional impulses for certain objects, e.g. money and wine. Scholars have therefore analyzed psychological diseases simply as dispositions for assent. This interpretation is incomplete, I argue, and should be augmented with the claim that psychological disease also affects what kind of action-guiding impressions are created prior to giving assent. (...) This proposal respects the Stoic insistence that impression-formation, no less than assent, is an activity of reason. In so far as the wine-lover’s reason is corrupted in a different way from the money-lover’s, the two vicious agents will form different action-guiding impressions when faced with similar stimuli. Here I juxtapose the Stoic account of expertise, according to which experts form more precise action-guiding impressions compared to the amateur, in virtue of possessing a system of grasps (katalēpseis). So expertise enhances, whereas psychological disease degrades, the representational fidelity of the impressions that prefigure action. With these commitments, the Stoics can be seen to offer a nuanced and principled theory of cognitive penetration and to anticipate some recent proposals in epistemology and cognitive science. (shrink)

A dispute in the form of rival interpretations of Carneades arose in the New Academy about whether the wise person is permitted to form opinions. One party rejected opinion; the other defended it. Because the terms enjoy a certain currency, the positions are here labelled ‘radical’ and ‘moderate’ respectively. This essay tackles the question whether and how they differed. It argues that the disagreement was less about human epistemic capacities than about the standards and aspirations against which they should be (...) measured and that Cicero, our principal source, was a consistent adherent of the ‘radical’ party. (shrink)

This paper examines some neglected Chrysippean fragments on insecure apprehension (κατάληψις). First, I present Chrysippus’ account of how non-Sages can begin to fortify their insecure apprehension and upgrade it into knowledge (ἐπιστήμη). Next, I reconstruct Chrysippus’ explanation of how sophisms and counter-arguments lead one to abandon one’s insecure apprehension. One such counter-argument originates in the sceptical Academy and targets the Stoic claim that insecure apprehension can be acquired on the basis of custom (συνήθεια). I show how Chrysippus could defend the (...) possibility of custom-based apprehension, while also denying that there is custom-based knowledge. (shrink)