16. We experience in ourselves the fact of multitude in the simple substance, when we find that the least thought of which we are conscious includes a variety in its object. Accordingly, all who admit that the soul is a simple substance, are bound to admit this multitude in the Monad, and Mr. Boyle should not have found any difficulty in this admission, as he has done in his dictionary—Art. Rorarius. 17. Besides, it must be confessed that Perception and its consequences are inexplicable by mechanical causes—that is to say, by figures and motions. If we imagine a machine so constructed as to produce thought, sensation, perception, we may conceive it magnified—the same proportions being preserved—to such an extent that one might enter it like a mill. This being supposed, we should find in it on inspection only pieces which impel each other, but nothing which can explain a perception. It is in the simple substance, therefore—not in the compound, or in machinery—that we must look for that phenomenon; and in the simple substance we find nothing else—nothing, that is, but perceptions and their changes. Therein also, and therein only, consist all the internal acts of simple substances. 18. We might give the name of Entelechies to all simple substances or created Monads, inasmuch as there is in them a certain completeness (perfection), (ἔχουσι τὸ ἔντελες). There is a sufficiency (αὐτάρκεια) which makes them the sources of their own internal actions, and, as it were, incorporeal automata. 19. If we choose to give the name of soul to all that has perceptions and desires, in the general sense which I have just indicated, all simple substances or created Monads may be called souls. But as sentiment is something more than simple perception, I am willing that the general name of Monads and Entelechies shall suffice for those simple substances which have nothing but perceptions, and that the term souls shall be confined to those whose perceptions are more distinct, and accompanied by memory. 20. For we experience in ourselves a state in which we remember nothing, and have no distinct perception, as when we are in a swoon or in a profound and dreamless sleep. In this state the soul does not differ sensibly from a simple Monad; but since this state is not permanent, and since the soul delivers herself from it, she is something more.