A considerable amount has already been said about Vygotsky’s debt to his sources, particularly Marx, Hegel and Spinoza. The object of this chapter is to cover several aspects of his relation to his sources not mentioned previously. This has three purposes. First, to set the scene for the next chapter on method, by further emphasising Vygotsky’s debt to his predecessors. This is necessary because Vygotsky himself often gives the impression that he began his investigations with just empirical data and a method, when in fact he clearly began with theoretical preconceptions, derived from his predecessors, and a method. Second, to explain in more detail how Vygotsky could claim to follow Marx’s historical materialism, when in some respects he clearly opposed aspects of it. Third, to consider some rival views of Vygotsky’s background.