Frogs and parasites, worms and infusoria—are these worth the attention of a serious man? They have a less imposing appearance than planets and asteroids, I admit, but they are nearer to us, and admit of being more intimately known; and because they are thus accessible, they become more important to us. The life that stirs within us is also the life within them. It is for this reason, as I said at the outset, that although man's noblest study must always be man, there are other studies less noble, yet not therefore ignoble, which must be pursued, even if only with a view to the perfection of the noblest. Many men, and those not always the ignorant, whose scorn of what they do not understand is always ready, despise the labours which do not obviously and directly tend to moral or political advancement. Others there are, who, fascinated by the grandeur of Astronomy and Geology, or by the immediate practical results of Physics and Chemistry, disregard all microscopic research as little better than dilettante curiosity. But I cannot think any serious study is without its serious value to the human race; and I know that the great problem of Life can never be solved while we are in ignorance of its simpler forms. Nor can anything be more unwise than the attempt to limit the sphere of human inquiry, especially by applying the test of immediate utility. All truths are related; and however remote from our daily needs some particular truth may seem, the time will surely come when its value will be felt. To the majority of our countrymen during the Revolution, when the conduct of James seemed of incalculable importance, there would have seemed something ludicrously absurd in the assertion that the newly-discovered differential calculus was infinitely more important to England and to Europe than the fate of all the dynasties; and few things could have seemed more remote from any useful end than this product of mathematical genius; yet it is now clear to every one that the conduct of James was supremely insignificant in comparison with this discovery. I do not say that men were unwise to throw themselves body and soul into the Revolution; I only say they would have been unwise to condemn the researches of mathematicians.
Let all who have a longing to study Nature in any of her manifold aspects, do so without regard to the sneers or objections of men whose tastes and faculties are directed elsewhere. From the illumination of many minds on many points, Truth must finally emerge. Man is, in Bacon's noble phrase, the minister and interpreter of Nature; let him be careful lest he suffer this ministry to sink into a priesthood, and this interpretation to degenerate into an immovable dogma. The suggestions of apathy, and the prejudices of ignorance, have at all times inspired the wish to close the temple against new comers. Let us be vigilant against such suggestions, and keep the door of the temple ever open.
