Abstract
In Hellenistic philosophy, one can find contrasting evaluations of the argumentative use of merely conceivable states of affairs. On the one hand, Epicureans discard any proposal that has no plausibility from the point of view of someone in possession of the relevant expertise. On the other hand, Sceptics regularly invoke views which one might conceivably hold, irrespective of the view’s epistemic credentials or whether or not it has or has ever had actual proponents. Since thought experiments often introduce scenarios involving merely conceivable but non-actual states of affairs, the positions of Epicureans and Sceptics regarding conceivability can be transposed into different attitudes towards the method of thought experiments.