2. The sensations belong to the different organs of the senses--sight, hearing, touch, the muscular sense, &c. Whatever be the sense affected, one sensation has the same rights as the others, from the point of view of the cognition of external objects. It is impossible to distinguish them into subjective and objective, by giving to this distinction the meaning that certain sensations represent objects as they are, while certain others simply represent our manner of feeling. This is an illegitimate distinction, since all sensations have the same physiological condition, the excitement of a sensory nerve, and result from the properties of this nerve when stimulated. 3. Consequently, it is impossible for us to form a conception of matter in terms of movement, and to explain by the modalities of movement the properties of bodies; for this theory amounts to giving to certain sensations, especially those of the muscular sense, the hegemony over the others. We cannot explain, we have not the right to explain, one sensation by another, and the mechanical theory of matter has simply the value of a symbol. FOOTNOTES: [Footnote 10: See p. 22, _sup._--ED.] [Footnote 11: See J. S. MILL'S _Examination of Sir Wm. Hamilton's Philosophy_, chap. x. p. 176, _et. seq._] [Footnote 12: See p. 18, _sup._--ED.] BOOK II THE DEFINITION OF MIND CHAPTER I THE DISTINCTION BETWEEN COGNITION[13] AND ITS OBJECT After having thus studied matter and reduced it to sensations, we shall apply the same method of analysis to mind, and inquire whether mind possesses any characteristic which allows it to be distinguished from matter. Before going any further, let me clear up an ambiguity. All the first part of this work has been devoted to the study of what is known to us in and by sensation; and I have taken upon myself, without advancing any kind of justifying reason, to call that which is known to us, by this method, by the name of matter, thus losing sight of the fact that matter only exists by contra-distinction and opposition to mind, and that if mind did not exist, neither would matter. I have thus appeared to prejudge the question to be resolved.