Full Idea
The guiding principle of the whole body is the mind or intellect, which is firmly lodged in the mid-region of the breast. Here is felt fear and alarm, and the caressing pulse of joy. Here, then is the seat of the intellect and mind.
Gist of Idea
The mind is in the middle of the breast, because there we experience fear and joy
Source
Lucretius (On the Nature of the Universe [c.60 BCE], III.140)
Book Reference
Lucretius: 'On the Nature of the Universe', ed/tr. Latham,Ronald [Penguin 1951], p.100
A Reaction
Even by this date thinking people were not clear that the mind is in the brain. They paid insufficient attention to head injuries. The emotions are felt to have a location, but intellect and principles are not.