The theme of the two philosophers, the optimist and the pessimist, appears very often in Dutch seventeenth century painting. Democritus of Abdera (c460/457BC - after 405BC) and Heraclitus (working c500BC) were greatly respected in the 17th century. Democritus, one of whose observations was that fear of death should not spoil life, had a reputation for cheerfulness.  Unfortunately, the scientific work that he has also done had been lost, and his main finding, the fact that matter was divided into atoms, was only known from secondary sources. Heraclitus, the melancholic, was also a scientist and was deeply concerned with self-knowledge and the realisation that the individual had to be reliant on a natural world order. The artist seems to have been well aware of these distinctions and this depiction of the two philosophers is one of the earliest known. Later depictions include those by Jan van Bijlert (q.v.), (Utrecht, Centraal Museum) Jacob Jordaens (q.v.), (Brunswick, Herzog Anton Ulrich-Museum) and Salvator Rosa (q.v.), (St. Petersburg, Hermitage and Vienna, Kunsthisthorisches Museum).

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