From Raimond Gaita’s A Common Humanity: Thinking About Love and Truth and Justice (150):

Optimism and pessimism are, anyhow, relatively trivial dispositions of personality. One can be a pessimist in the sense that one is disposed to take a gloomy view of prospects in most situations, seeing in them more reason to predict ill than good, and one can combine this with a temperamental melancholia, yet respond joyously to life as a gift.