perfect strictness that the subject of the exterior phenomena has the character of the latter, and that the subject of the phenomena of consciousness has the character of the former; that the one is solid and extended, and that the other is neither solid nor extended. Finally, as that which is solid and extended is divisible, and as that which is neither solid nor extended is indivisible, hence divisibility is attributed to the solid and extended subject, and indivisibility attributed to the subject which is neither extended nor solid. Who of us, in fact, does not believe himself an indivisible being, one and identical, the same yesterday, to-day, and to-morrow? Well, the word body, the word matter, signifies nothing else than the subject of external phenomena, the most eminent of which are form, impenetrability, solidity, extension, divisibility. The word mind, the word soul, signifies nothing else than the subject of the phenomena of consciousness, thought, will, sensation, phenomena simple, unextended, not solid, etc. Behold the whole idea of spirit, and the whole idea of matter! See, therefore, all that must be done in order to bring back matter to spirit, and spirit to matter: it is necessary to pretend that sensation, volition, thought, are reducible in the last analysis to solidity, extension, figure, divisibility, etc., or that solidity, extension, figure, etc., are reducible to thought, volition, sensation." 1st Series, vol. iii., lecture I, _Locke_. "Locke pretends that we cannot be certain _by the contemplation of our own ideas_, that matter cannot think; on the contrary, it is in the contemplation itself of our ideas that we clearly perceive that matter and thought are incompatible. What is thinking? Is it not uniting a certain number of ideas under a certain unity? The simplest judgment supposes several terms united in a subject, one and identical, which is _me_. This identical _me_ is implied in every real act of knowledge. It has been demonstrated to satiety that comparison exacts an indivisible centre that comprises the different terms of the comparison. Do you take memory? There is no memory possible without the continuation of the same subject that refers to self the different modifications by which it has been successively affected. Finally, consciousness, that indispensable condition of intelligence,--is it not the sentiment of a single being? This is the reason why each man cannot think without saying _me_, without affirming that he is himself the identical and one subject of his thoughts. I am _me_ and always _me_, as you are always yourself in the most different acts of your life. You are not more yourself to-day than you were yesterday, and you are not less yourself to-day than you were yesterday. This identity and this indivisible unity of the _me_ inseparable from the least thought, is what is called its spirituality, in opposition to the evident and necessary characters of matter. By what, in fact, do you