Full Idea
Thales seems, from what is recorded of him, to have supposed that the soul is something productive of movement, if he really said that the magnet has soul because it produces movement in iron.
Clarification
'Soul' is the Greek word 'psuché', which covers mind and consciousness and life
Gist of Idea
Thales must have thought soul causes movement, since he thought magnets have soul
Source
report of Thales (fragments/reports [c.585 BCE]) by Aristotle - De Anima 405a20
Book Reference
Aristotle: 'De Anima (On the Soul)', ed/tr. Lawson-Tancred,H.C. [Penguin 1986], p.135