Full Idea
Some think the soul is the heart; Empedocles holds that the soul is blood in the heart; others said one part of the brain claimed the primacy of soul; others say the heart or brain are habitations of the soul; while others identify soul and breath.
Gist of Idea
The soul is the heart, or blood in the heart, or part of the brain, of something living in heart or brain, or breath
Source
M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.ix.17-19)
Book Reference
Cicero: 'Tusculan Disputations', ed/tr. King,J.E. [Harvard Loeb 1927], p.23
A Reaction
A nice survey of views. Note that many of them identify the psuché/anima with physical parts of the body; only the fourth option seems to be dualist. This is despite the contemptuous response to Democritus' atomist theory of soul.