“1. The monad, of which we will speak here, is nothing else than a simple substance, which goes to make up compounds; by simple, we mean without parts.”
“2. There must be simple substances because there are compound substances; for the compound is nothing else than a collection or aggregatum of simple substances.”
“3. Now, where there are no constituent parts there is possible neither extension, nor form, nor divisibility. These monads are the true atoms of nature, and, in a word, the elements of things.”
“4. Their dissolution, therefore, is not to be feared and there is no way conceivable by which a simple substance can perish through natural means.”
“5. For the same reason there is no way conceivable by which a simple substance might, through natural means, come into existence, since it can not be formed by composition.”
“6. We may say then, that the existence of monads can begin or end only all at once, that is to say, the monad can begin only through creation and end only through annihilation. Compounds, however, begin or end by parts.”
“9. Each monad, indeed, must be different from every other monad. For there are never in nature two beings which are exactly alike, and in which it is not possible to find a difference either internal or based on an intrinsic property.”
“10. I assume it as admitted that every created being, and consequently the created monad, is subject to change, and indeed that this change is continuous in each.”
“11. It follows from what has just been said, that the natural changes of the monad come from an internal principle, because an external cause can have no influence on its inner being.”
“12. Now besides this principle of change there must also be in the monad a variety which changes. This variety constitutes, so to speak, the specific nature and the variety of the simple substances.”
“13. This variety must involve a multiplicity in the unity or in that which is simple. For since every natural change takes place by degrees, there must be something which changes and something which remains unchanged, and consequently there must be in the simple substance a plurality of conditions and relations, even though it has no parts.”
“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.”
“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.”
“26. The memory furnishes a sort of consecutiveness which imitates reason but is to be distinguished from it. We see that animals when they have the perception of something which they notice and. of which they have had a similar previous perception, are led by the representation of their memory to expect that which was associated in the preceding perception, and they come to have feelings like those which they had before. For instance, if a stick be shown to a dog, he remembers the pain which it has caused him and he whines or runs away.”
“27. The vividness of the picture, which comes to him or moves him, is derived either from the magnitude or from the number of the previous perceptions. For, oftentimes, a strong impression brings about, all at once, the same effect as a long-continued habit or as a great many reiterated, moderate perceptions.”
“28. Men act in like manner as animals, in so far as the sequence of their perceptions is determined only by the law of memory, resembling the empirical physicians who practice simply, without any theory, and we are empiricists in three-fourths of our actions. For instance, when we expect that there will be daylight tomorrow, we do so empirically, because it has always happened so up to the present time. It is only the astronomer who uses his reason in making such an affirmation.”
“29. But the knowledge of eternal and necessary truths is that which distinguishes us from mere animals and gives us reason and the sciences, thus raising us to a knowledge of ourselves and of God. This is what is called in us the Rational Soul or the Mind.”
“30. It is also through the knowledge of necessary truths and through abstractions from them that we come to perform Reflective Acts, which cause us to think of what is called the I, and to decide that this or that is within us. it is thus, that in thinking upon ourselves we think of being, of substance, of the simple and compound, of a material thing and of God himself, conceiving that what is limited in us is in him without limits. These reflective acts furnish the principal objects of our reasonings.”
“31. Our reasoning is based upon two great principles: first, that of contradiction, by means of which we decide that to be false which involves contradiction and that to be true which contradicts or is opposed to the false.”
“32. And second, the principle of sufficient reason, in virtue of which we believe that no fact can be real or existing and no statement true unless it has a sufficient reason why it should be thus and not otherwise. Most frequently, however, these reasons cannot be known by us.”
“33. There are also two kinds of truths: those of reasoning and those of fact. The truths of reasoning are necessary, and their opposite is impossible. Those of fact, however, are contingent, and their opposite is possible. When a truth is necessary, the reason can be found by analysis in resolving it into simpler ideas and into simpler truths until we reach those which are primary.”
“34. It is thus that with mathematicians the speculative theorems and the practical canons are reduced by analysis to definitions, axioms, and postulates.”
“35. There are finally simple ideas of which no definition can be given. There are also the axioms and postulates or, in a word, the primary principles which cannot be proved and, indeed, have no need of proof. These are identical propositions whose opposites involve express contradictions.”
“36. But there must be also a sufficient reason for contingent truths or truths of fact; that is to say, for the sequence of the things which extend throughout the universe of created beings, where the analysis into more particular reasons can be continued into greater detail without limit because of the immense variety of the things in nature and because of the infinite division of bodies. There is an infinity of figures and of movements, present and past, which enter into the efficient cause of my present writing, and in its final cause there are an infinity of slight tendencies and dispositions of my soul, present and past.”
“37. And as all this detail again involves other and more detailed contingencies, each of which again has need of a similar analysis in order to find its explanation, no real advance has been made. Therefore, the sufficient or ultimate reason must needs be outside of the sequence or series of these details of contingencies, however infinite they may be.”
“38. It is thus that the ultimate reason for things must be a necessary substance, in which the detail of the changes shall be present merely potentially, as in the fountainhead, and this substance we call God.”
“43. It is true, furthermore, that in God is found not only the source of existences, but also that of essences, in so far as they are real. In other words, he is the source of whatever there is real in the possible. This is because the Understanding of God is in the region of eternal truths or of the ideas upon which they depend, and because without him there would be nothing real in the possibilities of things, and not only would nothing be existent, nothing would be even possible.”
“44. For it must needs be that if there is a reality in essences or in possibilities or indeed in the eternal ‘truths, this reality is based upon something existent and actual, and, consequently, in the existence of the necessary Being in whom essence includes existence or in whom possibility is sufficient to produce actuality.”
“45. Therefore God alone (or the Necessary Being) has this prerogative that if he be possible he must necessarily exist, and, as nothing is able to prevent the possibility of that which involves no bounds, no negation and consequently, no contradiction, this alone is sufficient to establish a priori his existence. We have, therefore, proved his existence through the reality of eternal truths. But a little while ago we also proved it a posteriori, because contingent beings exist which can have their ultimate and sufficient reason only in the necessary being which, in turn, has the reason for existence in itself.”
“48. In God are present: power, which is the source of everything; knowledge, which contains the details of the ideas; and, finally, will, which changes or produces things in accordance with the principle of the greatest good. To these correspond in the created monad, the subject or basis, the faculty of perception, and the faculty of appetition. In God these attributes are absolutely infinite or perfect, while in the created monads or in the entelechies (perfectihabies, as Hermolaus Barbarus translates this word), they are imitations approaching him in proportion to the perfection.”
“49. A created thing is said to act outwardly in so far as it has perfection, and to be acted upon by another in so far as it is imperfect. Thus action is attributed to the monad in so far as it has distinct perceptions, and passion or passivity is attributed in so far as it has confused perceptions.”
“56. Now this interconnection, relationship, or this adaptation of all things to each particular one, and of each one to all the rest, brings it about that every simple substance has relations which express all the others and that it is consequently a perpetual living mirror of the universe.”
“57. And as the same city regarded from different sides appears entirely different, and is, as it were multiplied respectively, so, because of the infinite number of simple substances, there are a similar infinite number of universes which are, nevertheless, only the aspects of a single one as seen from the special point of view of each monad.”