It must be admitted, however, that the highest evidence and safeguard of truth is application.  In every other science, the utility test is final.  The great parent sciences—­mathematics, physics, chemistry, physiology—­have each a host of filial dependents, in close contact with the supply of human wants; and the success of the applications is the testimony to the truth of the sciences applied.  Thus, although we may not narrow the sphere of truth to bread and butter, yet we have no surer test of the truth itself.  Our trade requires navigation, and navigation verifies astronomy; and, but for navigation, we may be pretty confident that astronomy would now have very little accuracy to boast of.

To come then to the practical bearings or outgoings of psychology, assisted by logic.  My contention is that the parent sciences and the filial sciences should be carried on together; that theses should be extracted by turns from all; that the lights thus obtained would be mutual.  I will support the position by a review of the subjects thus drawn into the metaphysical field.

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[PROBLEMS OF EDUCATION.]

Foremost among these applied sciences I would place EDUCATION, the subject of the day.  The priority of mention is due not so much to its special or pre-eminent importance, as to its being the most feasible and hopeful of the practical applications of conjoined psychology and logic.  I say this, however, with a more express eye to intellectual education.  I deem it quite possible to frame a practical, science applicable to the training of the intellect that shall be precise and definite in a very considerable measure.  The elements that make up our intellectual furniture can be stated with clearness; the laws of intellectual growth or acquisition are almost the best ascertained generalities of the human mind; even the most complicated studies can be analyzed into their components, partly by psychology and partly by the higher logic.  In a word, if we cannot make a science of education, as far as Intellect is concerned, we may abandon metaphysical study altogether.

I do not speak with the same confidence as to moral education.  There has long been in existence a respectable rule-of-thumb practice in this region, the result of a sufficiently wide experience.  There are certain psychological laws, especially those relating to the formation of moral habits, that have a considerable value; but to frame a theory of moral education, on a level in a point of definiteness with the possible theory of intellectual education, is a task that I should not like to have imposed upon me.  In point of fact, two problems are joined in one, to the confusion of both.  There is first the vast question of moral control, which stretches far and wide over many fields, and would have to be tracked with immense labour:  it belongs to the arts of government; it comes under moral suasion,