When we turn from words like these to the actual work which Bacon did, it is hard not to feel a certain disappointment. He did not thoroughly understand the older philosophy which he attacked. His revolt from the waste of human intelligence which he conceived to be owing to the adoption of a false method of investigation blinded him to the real value of deduction as an instrument of discovery; and he was encouraged in his contempt for it as much by his own ignorance of mathematics as by the non-existence in his day of the great deductive sciences of physics and astronomy. Nor had he a more accurate prevision of the method of modern science. The inductive process to which he exclusively directed men's attention bore no fruit in Bacon's hands. The "art of investigating nature" on which he prided himself has proved useless for scientific purposes, and would be rejected by modern investigators. Where he was on a more correct track he can hardly be regarded as original. "It may be doubted," says Dugald Stewart, "whether any one important rule with regard to the true method of investigation be contained in his works of which no hint can be traced in those of his predecessors." Not only indeed did Bacon fail to anticipate the methods of modern science, but he even rejected the great scientific discoveries of his own day. He set aside with the same scorn the astronomical theory of Copernicus and the magnetic investigations of Gilbert. The contempt seems to have been fully returned by the scientific workers of his day. "The Lord Chancellor wrote on science," said Harvey, the discoverer of the circulation of the blood, "like a Lord Chancellor."