Full Idea
Early thinkers try only to describe the soul, but they fail to go into any kind of detail about the body which is to receive the soul, as if it were possible (as it is in the Pythagorean tales) for just any old soul to be clothed in just any old body.
Gist of Idea
Early thinkers concentrate on the soul but ignore the body, as if it didn't matter what body received the soul
Source
Aristotle (De Anima [c.329 BCE], 407b20)
Book Reference
'The First Philosophers', ed/tr. Waterfield,Robin [OUP 2000], p.96
A Reaction
Precisely. Anyone who seriously believes that a human mind can be reincarnated in a flea needs their mind examined. Actually they need their brain examined, but that probably wouldn't impress them. I can, of course, imagine moving into a flea.