Phlegmatikos

Phlegmatikos is a term from ancient Greek medicine used to describe a specific temperament associated with the phlegm humor. The word derives from Greek phlegma, meaning phlegm, and the adjective φλεγματικός (phlegmatikós); in Latin it became phlegmaticus, and in English phlegmatic or phlegmatical. In humoral theory, phlegm was thought to be produced by the brain and to yield a cold and moist disposition, giving rise to a calm, steady, and emotionally restrained character.

In classical temperament theory, phlegmatikos is one of the four temperaments, alongside sanguine, choleric, and melancholic. The phlegmatic temperament was described as even-tempered, patient, reliable, and thoughtful, but also as sluggish, indolent, or emotionally indifferent by some observers. This blend of traits was interpreted as consistency and endurance in daily life, work, and social relations, tempered by a tendency toward inaction or slow response.

Historical use of the concept spanned ancient Greek and Roman medical writers, continued through medieval and Renaissance thought, and influenced later European personality discourse. While the four‑humour framework is obsolete in modern medicine and psychology, the term phlegmatic survives in everyday language as a metaphor for a calm, reserved, or unemotional demeanor. In contemporary contexts it is typically understood descriptively rather than as a biological diagnosis, and it is often contrasted with other common descriptors such as sanguine, choleric, and melancholic.