to believe that spirits alone are monads and that there are no souls of animals or other entelechies, and it has led them to make the common confusion between a protracted period of unconsciousness and actual death. They have thus adopted the Scholastic error that souls can exist entirely separated from bodies, and have even confirmed ill-balanced minds in the belief that souls are mortal.
15. The action of the internal principle which brings about the change or the passing from one perception to another may be called appetition. It is true that the desire (l'appetit) is not always able to attain to the whole of the perception which it strives for, but it always attains a portion of it and reaches new perceptions.
16. We, ourselves, experience a multiplicity in a simple substance, when we find that the most trifling thought of which we are conscious involves a variety in the object. Therefore all those who acknowledge that the soul is a simple substance ought to grant this multiplicity in the monad, and Monsieur Bayle should have found no difficulty in it, as he has done in his Dictionary, article Rorarius.
17. It must be confessed, however, that perception, and that which depends upon it, are inexplicable by mechanical causes, that is to say, by figures and motions. Supposing that there were a machine whose structure produced thought, sensation, and perception, we could conceive of it as increased in size with the same proportions until one was able to enter into its interior, as he would into a mill. Now, on going into it he would find only pieces working upon one another, but never would he find anything to explain perception. It is accordingly in the simple substance, and not in the compound nor in a machine that the perception is to be sought. Furthermore, there is nothing besides perceptions and their changes to be found in the simple substance. And it is in these alone that all the internal activities of the simple substance can consist.
18. All simple substances or created monads may be called entelechies, because they have in themselves a certain perfection. There is in them a sufficiency which makes them the source of their internal activities, and renders them, so to speak, incorporeal Automatons.
19. If we wish to designate as soul everything which has perceptions and desires in the general sense that I have just explained, all simple substances or created monads could be called souls. But since feeling is something more than a mere perception I think that the general name of monad or entelechy should suffice for simple substances which have only perception, while we may reserve the term Soul for those whose perception is more distinct and is accompanied by memory.
20. We experience in ourselves a state where we remember nothing and where we have no distinct perception, as in periods of fainting, or when we are overcome by a profound, dreamless sleep. In such a state the soul does not sensibly differ at all from a simple monad. As this state, however, is not permanent and the soul can recover from it, the soul is something more.
21. Nevertheless it does not follow at all that the simple substance is in such a state without perception. This is so because of the reasons given above; for it cannot perish, nor on the other hand would it exist without some affection and the affection is nothing else than its perception. When, however, there are a great number of weak perceptions where nothing stands out distinctively, we are stunned; as when one turns around and around in the same direction, a dizziness comes on, which makes him swoon and makes him able to distinguish nothing. Among animals, death can occasion this state for quite a period.
22. Every present state of a simple substance is a natural consequence of its preceding state, in such a way that its present is big with its future.
23. Therefore, since on awakening after a period of unconsciousness we become conscious of our perceptions, we must, without having been conscious of them, have had perceptions immediately before; for one perception can come in a 