Air, Water, Earth, Fire--The Psychological Types
One sees what one can best see oneself--C.G. Jung
Long before psychology developed its endlessly entertaining pastime of dividing human beings into types,Renaissance philosophy posited four basic temperaments based on the theory of the "humours' in the blood. These were the melancholic (earthy), the phlegmatic (watery), the sanguine (airy) and the choleric (fiery).
George Herbert , in one of his lighter moods wrote in 1640 (great year for chess) The choleric drinks, the Melancholic eats, the Phlegmatic sleeps.
What the sanguine does is left to the imagination, but as he is "ethereal" or airy we may assume that he probably philosophises.