{Reference Type}: Journal Article {Title}: Ancient philosophers on mental illness. {Author}: Ahonen M; {Journal}: Hist Psychiatry {Volume}: 30 {Issue}: 1 {Year}: Mar 2019 {Factor}: 0.579 {DOI}: 10.1177/0957154X18803508 {Abstract}: This article explores how the ancient philosophers from Plato to late antiquity understood mental illness. It outlines when, how and in what kind of contexts the phenomenon of mental illness was recognized in the ancient philosophical texts, how mental illness was understood in terms of the body-mind interaction, and how mental disorders of the medical kind were distinguished from non-medical psychic disturbances. It establishes that, while the philosophers mostly understood mental illness along the lines of ancient medical thinking, their ideas, for example on the nature and location of the soul, informed their theories of mental illness.