Arnold wrote to Clough of Keats that Keats did not understand that one ‘must begin with an Idea of the world, in order not to be prevailed over by the world's multifariousness’. Darwin is on Keats's side of this argument. He begins with the multifariousness of the world, is even prevailed over by it, and then uses it as both material and idea. Such an attitude in itself goes some way towards resolving the problem of first causes and of teleology. He refuses any precedent ‘Idea’ of the world from which to begin. This is not to suggest that he refuses theory, or that he believes facts to be authoritatively inert. In a letter to Fawcett in 1861 he made his position clear:

In his Reminiscences of his father Francis Darwin wrote that ‘it was as though he were charged with theorising power ready to flow into any channel on the slightest disturbance, so that no fact, however small, could avoid releasing a stream of theory’.