Abstract
Scholars have characterised the trial of the life of pleasure in Philebus 20b-21d as digressive or pejorative. I argue that it is neither: it is a thought experiment containing an important argument, in the form of a reductio, of the hypothesis that a life could be most pleasant without cognition. It proceeds in a series of steps, culminating in the precisely chosen image of the jellyfish. Understanding the intended resonance of this creature, and the sense in which it is deprived, is critical for reconstructing the argument, and yields new insight into Plato’s views on the minimal conditions for pleasure.