Greek philosopher, d. 475 B.C. The saying itself is based on a misunderstanding. In his edition of the Advancement (1974, p. 251), Arthur Johnston explains that Heraclitus is reported to have said that "the dry soul is the wisest and best". By a corruption in the Greek the sentence became "the dry light (lumen siccum) is the wisest soul". Heraclitus believed that the soul was a mixture of fire (the noble part) and water (the ignoble). The soul which has most fire he calls "dry". The saying and its later corruption are discussed in The Art and Thought of Heraclitus by Charles H. Kahn, Cambridge, 1979, pp. 245-54.