hiː kənsˈɪdɚd ðə hˈɑːɹt təbi ðə sˈiːt ʌv lˈaɪf, ænd nˈoʊɾɪst ðætðə lˈɛft vˈɛntɹɪkəl ɪz smˈɔːlɚ ænd θˈɪkɚ ðɐn ðə ɹˈaɪt.
He considered the heart to be the seat of life, and noticed that the left ventricle is smaller and thicker than the right.