Inasmuch as knowledge, real or supposed, must needs precede every act of the will, and as the adaptation of our actions to our purposes depends on the accuracy of our knowledge, *it is intrinsically fitting ** that our cognitive powers should be thoroughly developed and trained, and diligently employed.* Especially is this fitting, because—as has been already shown—it is through knowledge alone that we can bring our conduct into conformity with the absolute right, and there is nothing within the range of our possible knowledge, which may not become in some way connected with our agency as moral beings. It is of prime importance that what we seem to know we know accurately; and as it is through the senses that we acquire our knowledge, not only of the outward objects with which we are daily conversant, but of other minds than our own, *the education of the senses* is an obvious duty. There are few so prolific sources of social evil, injustice, and misery, as the falsehood of persons who mean to tell the truth, but who see or hear only in part, and supply the deficiencies of perception by the imagination. In the acquisition of knowledge of the highest interest and importance this same hindrance is one of the most frequent obstacles. The careless eye and the heedless ear waste for many minds a large portion of the time ostensibly given to serious pursuits, and render their growth pitifully slow and scanty as compared with their means of culture. The senses may, especially in early life, be trained to alertness and precision, so that they shall carry to the mind true and full reports of what they see and hear; and it is only by such training that the perceptive faculties can accomplish the whole work for which they are designed and fitted. There are, also, interior senses, *apprehensive powers of the mind*, which equally crave culture, and which depend for their precision and force on careful education and diligent use. Mere observation, experience, or study, cannot give knowledge that will be of any avail. One may have a largely and variously stocked memory, and yet be unable to employ its contents to his own advantage or to the benefit of others. Indeed, there are minds that are paralyzed by being overloaded,—by taking in freight faster than they have room for it. It is only materials which the mind has made its own, incorporated into its substance, that it can fully utilize. Knowledge must be acted upon by the understanding, the reason, the judgment, before it can be transmuted into wisdom, and employed either in the acquisition of new truth or in the conduct of life. Mental activity, then, is a duty; for if we are bound to preserve life, by parity of reason, we are bound to improve its quality and increase its quantity, and this cannot be done unless the intellectual powers are strengthened by diligent exercise, as well as nourished by the facts and truths which are the raw material of wisdom.