It has been my desire to render this work an aid to mental improvement. For this purpose, I have added practical suggestions on the cultivation of the several faculties. Earnestminded young men frequently err in their attempts at self-improvement. It has seemed to me, therefore, that a work of this kind would be manifestly imperfect, did it not directly, as well as indirectly, aid the student in his efforts to discipline and strengthen his intellectual energies. In order to encourage more extensive reading upon the subject than can be furnished in a text-book, I have added references to a number of works of easy access, specifying the places in which the topics treated of were discussed. In this labor, I have availed myself of the assistance of my former pupils, Mr. SAMUEL BROOKS, now instructor in Greek, in this University, and Mr. LUCIUS W. BANCROFT, of Worcester, Mass. To these gentlemen the student is indebted for whatever benefit he may derive from this feature of the work. For the many imperfections of this volume, the author consoles himself with the reflection, that it has been written and prepared for the press under the pressure of other important and frequently distracting avocations. In the humble hope. that it may, nevertheless, facilitate the study of this interesting department of human knowledge, it is, with diffidence, submitted to the judgment of the public. BROWN UNIVERSITY, Sept. 14, 1854. SECTION VIII.-The Sense of Sight, SECTION IX.- Acquired Perceptions, SECTION X.-The Nature of the Knowledge which we acquire by the -- INTRODUCTION. DEFINITION OF THE INTELLECTUAL POWERS. INTELLECTUAL PHILOSOPHY treats of the faculties of the human mind, and the laws by which they are governed. The only forms of existence which, in our present state, we are capable of knowing, are matter and mind. It is the mind alone that knows. When, therefore, we cognize matter, the object known, and the subject which knows, are numerically distinct. When, on the other hand, we cognize mind, the mind which knows and the mind which is known are numerically the same. The mind knows, and the mind is the object of knowledge. 1. The mind becomes cognizant of the existence and qualities of matter, that is, of the world external to itself, by means of the Perceptive faculties. It knows not what matter is, or what is the essence of matter, but only its qualities; that is, its power of affecting us in this or that manner. When we say, "This is gold," "This is gold," we do not pretend to know what the essence of gold is, but merely that there is something possessed of certain qualities, or powers of creating in us certain affections. 2. In a similar manner we become acquainted with the energies of our own mind. We are not cognizant of the mind itself, but only of the action of its faculties or sensibilities. When we think, remember, or reason; when we are joyful or sad, when we deliberate or resolve, we know that these several states of the mind exist, and. that they are predicated of the being whom I denominate I, or myself. The power by which we become cognizant to ourselves of these mental states is called Consciousness. When, by an act of volition, a particular mental state is made the object of distinct and continuous thought, the act is denominated Reflection. 3. An idea of perception or of consciousness terminates as soon as another idea succeeds it. It is perfect and complete within itself, and is not necessarily connected with anything else. I see a ball either at rest or in motion; I turn my eyes in another direction and perceive a tree or a house; in a moment afterwards they are both violently thrown down. I am conscious of several separate perceptions, which follow each other in succession. Each one of these mental acts is complete within itself, and might have been connected with no other. We find, however, that these ideas of perception are not thus disconnected. They do not terminate in themselves, but give occasion to other ideas of great importance; ideas which but for the acts of perception could never have existed. Thus, we saw a house standing, we now see it fallen; there at once arises in the mind the idea of a cause, or of something which has occasioned this change. Several ideas following in succession occasion the idea of duration. The existence of these secondary ideas under these circumstances is owing to the constitution of the human mind. itself. It suggests to us these ideas, which, when once conceived, are original and independent. This power of the mind is termed Original Suggestion. 4. The knowledge acquired both by our perceptive faculties and by consciousness, as well as much that is given us by original suggestion, is the knowledge of things or acts as individuals. We perceive single objects; we are con |