In Ancient Greek philosophy, Phren (Ancient Greek: φρήν, romanized: phrēn, lit. 'mind'; plural phrenes, φρένες) is the location of thought or contemplation.^[1] The kind of mental activity conducted in the Phren involves what 20th and 21 Century Western thinkers consider both feeling and thinking; scholars have remarked that Ancient Greeks located this activity in the torso as opposed to the head. ^{[2] [3]}

For example, phren is where Achilles considered his sadness about losing Briseis and his duty to join the Greeks against Troy.^[2] Phren, however, is not exclusively applied to humans. In Empedocles' system, Phren is a general psychological agent to which moral blame and praise can be extended,^[4] that darts through the universe as effluences, steers and controls the cosmos in the process and is the measure of what is harmonious and what is fit to exist.^[5] It is said that it is strongest at the region found beyond the universe where strife reigns.^[5]