Plato's striking figure of the ‘child in us’ at Phaedo 77e5 takes on an added lustre when viewed in the light of the theory of explanation Socrates develops between lOObl and 105c7.

Socrates' theory aims to explain why certain objects have certain properties: why something is beautiful (στ…κσλν, 100c4) or tall (100e5–6), or when a body will be sick (νοσσɛι, 105c3) or alive (ζῷν ἔσται, 105c9–10). Explanation is called for, Socrates thinks, when an object has a property its title to which is insecure, in the sense (to judge from 102b8–c8) that the object's having the property is not guaranteed by its being what it is. Thus Socrates wants an explanation, for example, of a person's being tall (102cl–9) or – the case of especial interest in the Phaedo – of a body's being alive.