- of any, at least, which shall be at once recognized and incorporated into the public mind. Even if completed in thought and expression by one man,-if it should have its Newton, yet its full acceptance by the public mind and assimilation with it would necessarily be slow. In astronomy, the true system was opposed to the popular conceptions and forms of speech, and more than one generation was required for it to permeate the masses and thoroughly control the habits of thought. But in that the proofs were open to popular apprehension, and, for the most part, there were no desires and passions to obstruct conviction. But of all the changes in society, none are so slow as those which are conditioned upon changes in language and character. Even Christianity itself, with its wonderful evidence and its divine power, is far from having taken full possession of the public mind in any community, and simply because it had these obstacles to encounter. But, as we have seen, perfection in moral science, to say nothing of other obstacles, can be reached only through changes both in language and in character. If terms absolutely new would not be demanded, yet some, like the heathen words for God, would require to be expanded and ennobled, while others would require to have their elasticity and capacity reduced; and then, the delicacy of moral feeling and accuracy of perception to be attained only through virtuous habits, would be indispensable. It follows from this that, in our cultivation of this field, we are not to be disappointed if we see no immediate or startling results. The changes to be anticipated are like those of geology in the formation of strata, sometimes more and sometimes less rapid, but always relatively slow. But since the progress of the science is so slow, and its TWO CLASSES OF SCIENCES. 35 completion has been so long delayed, it may be asked whether it is of any use. Are there not, it may be inquired, in our nature practical principles, which do and will control the course of human affairs with something like the certainty of instinct, and quite independent of scientific speculation? Within the memory of many this question has been put respecting various branches of physical science. It would not be put now. But respecting metaphysical and moral science there are those who put it with sincerity and earnestness. On this point, and as they are related to practical arts, there are two classes of sciences. In the one the science is wholly at the basis of the art, and is requisite to its results in any degree. The art of photography could not have been without chemistry, nor surgery without anatomy, nor the art of protecting buildings from lightning without the science of electricity. In such cases, and they are numerous, the science is first, and the practical results follow. The processes start from the sciences. In these cases no one questions the utility of science. In the other class the practical results are first and the sciences follow. The sciences start from the processes, which they simply recapitulate. Here science consists in the statement of the properties, the relations in space, and the successions in time of those things which our will cannot reach, or, if it can, cannot improve. Science may predict the place of a star; but the color of its light or the rapidity of its motion it cannot affect. God gives light and the eye, and we see; but we see no better after knowing the structure of the eye and the science of optics than before. Here the result is first, as perfect as it can be made, and the science is just a statement of the process by which the result was reached. It is in this class that the science of the mind belongs. Like the eye, its faculties are given, and act by their own law without reference to science, which can merely trace back and state such results as are common to all minds. It is solely with reference to these sciences that the question arises. To this question, What is the use? there are two replies. The first is, that, even in the sense of the word as used by the objector, these sciences are of use. The processes may be perfect; we may not be able to affect the results, and yet the sciences may be of use indirectly. We cannot change the number or movements of Jupiter's satellites; but by means of their eclipses we can calculate the longitude. Entomology will not enable us to change the structure or habits of an insect; but it may suggest a mode of saving our trees. The laws of the winds are not subject to our control; but by a knowledge of them we may shorten our voyage. Again, this class of sciences becomes greatly useful when the structures and processes of nature become deranged. When the eyes become flattened by age, science can remedy the defect, and when "A drop serene hath quenched their orb, Or dim suffusion veiled," it is by science alone that it can be removed. And so it is in most cases of displacement and derangement in the physical system. The science of anatomy, which is almost wholly at the basis of the art of surgery, would be of no practical use if nothing ever went wrong in the body. : A second reply to the objection urged is, that while we do not repudiate the conception of utility involved in what has just been said, we yet do not need it for the vindication of these sciences. We are capable of an inter USE OF STUDYING THE SCIENCE. 37 est in science for its own sake, which shows that we have an affinity with higher natures, and that the whole domain of the universe will finally be ours. The pleasure felt by the great discoverers of scientific truths is among the purest and most unselfish that can belong to man. It gives them a thought of God which they utter to the race, and it becomes a fountain of joy to millions. So it has been in astronomy. Every time the thought of God, as uttered by Newton, has been apprehended for the first time by any mind, there has been a commencement anew of the revolutions of the heavens, and the morning stars have sung together. And so would it be if the mighty forces and bright order that are without and afar could be seen to be, as they are, but a type and reflection of the forces and order within. Then would the great thought of God, not merely of a physical order in one department, but in all departments; and not of a physical order merely, but of one which should correspond in his one universe to a spiritual and moral order still more glorious, stand fully revealed, and should be a light and a joy forever. I have only to add, that our opinions of the laws and processes of our being may be so held as to affect those processes scarcely at all, and hence that the practical results of man's opinions on these points are often less beneficent and less mischievous than would naturally be supposed. In our minds, no less than in external nature, the forces are what they are, irrespective of any opinion of ours, and will act, and no theory has any direct tendency to eradicate or diminish them. In the man who believes in disinterested benevolence, the desires and passions and selfish forces may still have the ascendency, while he who holds to the selfish theory may be often moved by the natural impulses of benevolence and sympathy. So it is that |