§ 10. As Mr. Spencer is here considering science merely with reference to its importance in earning a livelihood, it is not beside the question to remark, that in a great number of instances, the knowledge of the science which underlies an operation confers no practical ability whatever. No one sees the better for understanding the structure of the eye and the undulatory theory of light. In swimming or rowing, a senior wrangler has no advantage over a man who is entirely ignorant about the laws of fluid pressure. As far as money-getting is concerned then, science will not be found to be universally serviceable. Mr. Spencer gives instances indeed, where science would prevent very expensive blundering; but the true inference is, not that the blunderers should learn science, but that they should mind their own business, and take the opinion of scientific men about theirs. “Here is a mine,” says he, “in the sinking of which many shareholders ruined themselves, from not knowing that a certain fossil belonged to the old red sandstone, below which no coal is found.” Perhaps they were misled by the little knowledge which Pope tells us is a dangerous thing. If they had been entirely ignorant, they would surely have called in a professional geologist, whose opinion would have been more valuable than their own, even though geology had taken the place of classics in their schooling. “Daily are men induced to aid in carrying out inventions which a mere tyro in science could show to be futile.” But these are men whose function it would always be to lose money, not make it, whatever you might teach them.[187] I have great doubt, therefore, whether the learning of sciences will ever be found a ready way of making a fortune. But directly we get beyond the region of pounds, shillings, and pence, I agree most cordially with Mr. Spencer that a rational knowledge has an immense superiority over empirical knowledge. And, as a part of their education, boys should be taught to distinguish the one from the other, and to desire rational knowledge. Much might be done in this way by teaching, not all the sciences and nothing else, but the main principles of some one science, which would enable the more intelligent boys to understand and appreciate the value of “a rational explanation of phenomena.” I believe this addition to what was before a literary education has already been made in some of our leading schools, as Harrow, Rugby, and the City of London.[188]