Beginning in approximately 1645, a radical change can be witnessed in Rembrandt’s style. The extroverted expressions and dynamism of his compositions give way to calm and psychological concentration. The physical vigour that is characteristic of Rembrandt’s earlier human figures is transformed into spiritual vigour. In many areas of the paintings thick brushstrokes hint at forms rather than defining them. The importance Rembrandt attaches to an apparently unfinished execution in his final years is surprising. According to Arnold Houbraken (1660-1719), one of Rembrandt’s earliest biographers, the artist stated that “a painting is finished when the master has achieved his aims”. With this statement Rembrandt asserted his independence as a creator and also his belief that the aims of painting go beyond merely capturing the appearance of things.