Mahoney responds to Sedley's rejoinder, with an explanation of why Plato might have wished to "stress the approximateness of the temporal reference": according to Mahoney, Plato thinks that the "corruption of the revolutions in our heads" begins when we first begin to perceive, but Plato would plausibly have regarded perception to begin, not exactly at birth, but rather 'around the time of birth', peri\ th_n ge/nesin:
Plato suggests that the disruption takes place at a very specific time: 'it was just then, at that very instant' (kai\ dh_ kai\ to&te e0n tw|~ paro&nti, 43 C7). When is this exactly? Sedley and Zeyl agree that the disruption occurs at birth, but this may not be accurate. The disruption begins to occur when a person first encounters external stimuli, which happens no later than the time of birth, but perhaps even earlier. An expectant mother often feels the movements of the child within her womb. It is not unreasonable to think that such movements are the reaction to soem stimulus that has been transmitted to the foetus within the womb. If so, then the disruptions to the revolutions begin even before birth. This would mean that we cannot make any general rule about the precise time at which human revolutions begin to be disrupted, so the most accurate way to describe the time at which these disruptions begin with with a suitably approximate expression such as peri\ th_n ge/nesin, 'around the time of birth', the exact phrase that Plato uses.But Mahoney's explanation contains a flaw. Can you see what it is? (A hint: it involves an equivocation.) And yet in spite of that his interpretation is, I think, ultimately sustainable, although on slightly different grounds.
But more of this on Monday, as I'll be travelling over the weekend.