 The pictures are not wonderful...".In 1955, examinations with X-rays and infrared photography at the laboratory of the Louvre revealed notable differences in treatment and caused this attribution to be dropped.Jacques Foucart (1982), Curator for Dutch and Fleming Painting at the Louvre, like Horst Gerson (1968) and Werner Sumowski (1983), attributes this work to Salomon Koninck (1609–1656), a Rembrandt imitator, dating it to around 1645 and titling it "Philosopher in Contemplation" or "Philosopher with an Open Book".