This analysis of A Dance to the Music of Time contains information on the meaning of the painting, the evolution of its composition, its visual sources and its critical content. There is also an examination of the nature of Giulio Rospigliosi's patronage and Poussin's importance in the eyes of British art collectors. The painting has often been taken as a statement of Poussin's own philosophy, but this text argues that his contribution was rather that of a painter, giving pictorial expression to the poetic and philosophical ideas of his patron.