The business with Ajay Naylor had been concluded to mutual satisfaction; she was not adverse to providing him rugs on commission, though she was less sanguine, even, than Audrey regarding the possibility of shipping off-planet.

Sharon Lee and Steve Miller. I Dare.

when, as sometimes happened, filial respect wore a little thin, at least these regrettable lapses did not last for long, and were not difficult for a man of his sanguine temperament to forget.

Georgette Heyer. The Grand Sophy.

Sanguine is a fairly common word, but it’s a bit disconcerting to look at the way sanguine is usually used compared to the dictionary definition of sanguine and its etymology. According to the American Heritage Dictionary, sanguine means:

  1. Of the color of blood; red.
    1. Of a healthy reddish color; ruddy: a sanguine complexion.
  2. Archaic Having blood as the dominant humor in terms of medieval physiology.
    1. Having the temperament and ruddy complexion formerly thought to be characteristic of a person dominated by this humor; passionate.
  3. Cheerfully confident; optimistic

(AHD).

Most of the time when we see or hear sanguine used today, it’s used in terms of the third definition; “Cheerfully confident; optimistic,” as in the quotation from Lee and Miller’s I Dare. But sometimes, we also see and hear sanguine and related words used to mean either “bloody, ” or the color of blood, as in the wine and fruit beverage sangria, a word that is cognate with sanguine.

Sanguine, and a cohort of cognates (like sangria), entered English by way of Old French, sanguin, derived from Latin sanguis, sanguin-, both of which mean “blood.” As I observed earlier, Modern English uses sanguine most often in its third meaning of “cheerfully confident; optimistic,” but the same root also gives us “sanguinary,” or “bloodthirsty.” The reason for this seeming contradiction derives from medieval medical terminology.

Physicians, beginning in the Classical era and flourishing In the middle ages (and continuing right through the early nineteen hundreds in a modified form), believed that perfect health consisted in a balance between the four humors. The humors were four bodily fluids (blood, bile, black bile, and phlegm) each of which each governed not only physical characteristics, but emotional states and qualities. If someone had an excess of blood it was the dominant humor and determined their basic psychological state or temperament. People of a sanguine humor or temperament were believed to have a cheerful disposition, one rich with good will, and hope. They were believed to readily fall in love. Such people were said to have a sanguine disposition.