The crucial problem Hume puts to himself is that between the two extreme positions of sensualistic empiricism and dogmatic rationalism a third position must be found which might do full justice to the non- sceptical and non-speculative philosophical intentions of his philosophy. In other words, Hume is in search of a common root which is related to the senses on the one hand and to reason on the other. Imagination is this common root between the opposing poles of sense and reason.