In the individual who dreams, the soul does not act more from itself, than it does in the man who is drunk, that is to say, who is modified by some spirituous liquor: or than it does in the sick man, when he is delirious, that is to say, when he is modified by those physical causes which disturb his machine, which obstruct it in the performance of its functions; or than it, does in him, whose brain is disordered: dreams, like these various states, announce nothing more than a physical confusion in the human machine, under the influence of which the brain ceases to act, after a precise and regular manner: this disorder may be traced to physical causes, such as the aliments--the humours--the combinations--the fermentations, which are but little analogous to the salutary state of man; from hence it will appear, that his brain is necessarily confused, whenever his body is agitated in an extraordinary manner. Do not let him, therefore, believe that his soul acts by itself, or without a cause, in any one moment of his existence; it is, conjointly with the body, submitted to the impulse of beings, who act on him necessarily, according to their various properties. Wine taken in too great a quantity, necessarily disturbs his ideas, causes confusion in his corporeal functions, occasions disorder in his mental faculties. If there really existed a being in Nature, with the capability of moving itself by its own peculiar energies, that is to say, able to produce motion, independent of all other causes, such a being would have the power of arresting itself, or of suspending the motion of the universe; which is nothing more than an immense chain of causes linked one to another, acting and re-acting by necessary immutable laws, and which cannot be changed, which are incapable of being suspended, unless the essences of every thing in it were changed, without the properties of every thing were annihilated. In the general system of the world, nothing more can be perceived than a long series of motion, received and communicated in succession, by beings capacitated to give impulse to each other: it is thus, that each body is moved by the collision of some other body. The invisible motion of some soul is to be attributed to causes concealed within himself; he believes that it is moved by itself, because he does not see the springs which put it in motion, or because he conceives those powers are incapable of producing the effects he so much admires: but, does he more clearly conceive, how a spark in exploding gunpowder, is capable of producing the terrible effects he witnesses? The source of his errors arise from this, that he regards his body as gross and inert, whilst this body is a sensible machine, which has necessarily an instantaneous conscience the moment it receives an impression; which is conscious of its own existence by the recollection of impressions successively experienced; memory by resuscitating an