[23] This classification of the human faculties, save some differences more nominal than real, is now generally adopted, and makes the foundation of the psychology of our times. See our writings, among others, 1st Series, Course of 1816, lectures 23 and 24: _Histoire du moi_; ibid., _Des faits de Conscience_; vol. iii., lecture 3, _Examen de la Theorie des Facultes dans Condillac_; vol. iv., lecture 21, _des Facultes selon Reid_; vol. v., lecture 8, _Examen de la Theorie de Kant_; 3d Series, vol iv., _Preface de la Premiere Edition, Examen des Lecons de M. Laromiguiere, Introduction aux Oeuvres de M. de Biran, etc._ [24] This lecture on the existence of universal and necessary principles, which was easily comprehended, in 1818, by an auditory to which long discussions had already been presented during the two previous years, appearing here without the support of these preliminaries, will not perhaps be entirely satisfactory to the reader. We beseech him to consult carefully the first volume of the 1st Series of our Course, which contains an abridgment, at least, of the numerous lectures of 1816 and 1817, of which this is a _resume_; especially to read in the third, fourth, and fifth volumes of the 1st Series, the developed analyses, in which, under different forms, universal and necessary principles are demonstrated as far as may be, and in the third volume of the 2d Series the lectures devoted to establish against Locke the same principles. LECTURE II. ORIGIN OF UNIVERSAL AND NECESSARY PRINCIPLES. _Resume_ of the preceding Lecture. A new question, that of the origin of universal and necessary principles.--Danger of this question, and its necessity.--Different forms under which truth presents itself to us, and the successive order of these forms: theory of spontaneity and reflection.--The primitive form of principles; abstraction that disengages them from that form, and gives them their actual form.--Examination and refutation of the theory that attempts to explain the origin of principles by an induction founded on particular notions. We may regard as a certain conquest of the experimental method and of true psychological analysis, the establishment of principles which at the same time that they are given to us by the surest of all experiences, that of consciousness, have a bearing superior to experience, and open to us regions inaccessible to empiricism. We have recognized such principles at the head of nearly all the sciences; then, searching among our different faculties for that which may have given them to us, we have ascertained that it is impossible to refer them to any other faculty than to that general faculty of knowing which we call reason, very different from reasoning, to which it furnishes its laws. That is the point at which we have arrived. But is it possible to stop there?