Leibniz to Arnauld

Hanover, July 14, 1686.

Monsieur:

As I have great deference for your judgment, I was glad to see that you moderated your censure after having seen my explanation of that proposition which I thought important and which appeared strange to you: "That the individual concept of each person involves once for all, all that will ever happen to him." From this at first you drew this consequence, namely, that from the single supposition that God resolved to create Adam, all the rest of the human events which happened to Adam and to his posterity would have followed by a fatalistic necessity, without God's having the freedom to make a change any more than he would have been able not to create a creature capable of thought after having resolved to create me.

To which I replied, that the designs of God regarding all this universe being inter-related conformably to his sovereign wisdom, he made no resolve in respect to Adam without taking into consideration everything which had any connection with him. It was therefore not because of the resolve made in respect to Adam but because of the resolution made at the same time in regard to all the rest (to which the former involves a perfect relationship), that God formed the determination in regard to all human events. In this it seems to me that there was no fatalistic necessity and nothing contrary to the liberty of God any more than there is in this generally accepted hypothetical necessity which God is under of carrying out what he has resolved upon.

You accept, M., in your reply, this inter-relation of the divine resolves which I put forward and you even have the sincerity to acknowledge that at first you understood my proposition wholly in a different sense, "Because it is not customary for example" (these are your words), "to consider the specific concept of a sphere in relation to its representation in the Divine understanding but in relation to that which it is itself." And you thought "that it was thus also with respect to the individual concept of each person."

On my part, I thought that complete and comprehensible concepts are represented in the divine understanding as they are in themselves but now that you know what my thought is, you say it is sufficient to conform to it and to inquire if it removes the difficulty. It seems then that you realize that my position as explained in this way, to mean complete and comprehensive concepts such as they are in the divine understanding, is not only innocent but is, indeed, right, for here are your words, "I agree that the knowledge which God had of Adam when he resolved to create him involved everything that has happened to him and all that has happened and will happen to his posterity, and therefore, taking the individual concept of Adam in this sense, what you say is very certain." We will go on to see very soon in what the difficulty which you still find consists. Yet I will say one word in regard to the cause for the difference which there is here between concepts of space and those of individual substances, rather in relation to the divine will than in relation to the simple understanding. This difference is because the most abstract specific concepts embrace only necessary or eternal truths which do not depend upon the decrees of God (whatever the Cartesians may say about this whom it seems you have not followed at this point), but the concepts of individual substances which are complete, and sufficient to identify entirely their subjects and which involve consequently truths that are contingent or of fact, namely, individual circumstances of time, of space, etc.- such substances, I say, should also involve in their concept taken as possible, the free decrees or will of God, likewise taken as possible, because these free decrees are the principal sources for existences or facts while essences are in the divine understanding before his will is taken into consideration.

This will suffice to make clearer all the rest and to meet the difficulties which still seem to remain in my explanation. For you continue in this way: "But it seems that after that the question still remains, and here is my difficulty, whether the connection between these objects, I mean Adam and human events, is such, of itself, independently of all the free decrees of God or if it is dependent upon them. That is to say, whether God knows what will happen to Adam and his posterity only because of the free decrees by which God has ordained all that will happen to them, or if there is, independently of these decrees, between Adam on the one hand and that which has happened to him and will happen to him and to his posterity on the other, an intrinsic and necessary connection." It seems to you that I will take the latter alternative because I have said, "That God has found among the possibilities an Adam accompanied by certain individual circumstances and who, among other predicates, has also this one of having in time a certain posterity." Now you suppose that I agree that the possibilities are possible before all the free decrees of God; supposing, therefore, this explanation of my position according to the latter alternative, you think that it has insurmountable difficulties. For there are, as you say with good reason, "an infinity of human events that happen by the expressly particular ordinances of God. Among others, the Jewish and Christian religions and, above all, the Incarnation of the divine word. And I do not know how one could say that all this (which has happened by the free decrees of God), could be involved in the individual concept of the possible Adam. Whatever is considered as possible ought to have everything that could be conceived as being under this concept, independently of the divine decrees."

I wish to state your difficulty exactly, Monsieur, and this is the way in which I hope to satisfy it entirely to your own taste. For it must needs be that it can be resolved, since we cannot deny that there is truly a certain concept of Adam accompanied by all its predicates and conceived as possible, which God knew before resolving to create him, as you have just admitted. I think, therefore, that the dilemma of the alternative explanation which you have proposed may have a mean, and the connection which I conceive of between Adam and human events is intrinsic but it is not necessarily independent of the free decrees of God because the free decrees of God taken as possible enter into the concept of the possible Adam, and when these same decrees become actual they are the cause of the actual Adam. I agree with you, in opposition to the Cartesians, that the possibles are possible before all the actual decrees of God, but the decrees themselves, must be regarded also as possibles. For the possibilities of the individual or of contingent truths involve in their concept the possibility of their causes, that is to say, the free decrees of God in which they are different from generic possibilities or from eternal truths. These latter depend solely upon the understanding of God without  presupposing any will, as I have explained it above.

This might be enough, but in order to make myself better understood, I will add that I think there were an infinity of possible ways of creating the world according to the different plans which God might have formed and that each possible world depends upon certain principal plans or designs of God that are his own; that is to say, upon certain primary free decrees conceived sub ratione possibilitatis, or upon certain laws of the general order of this possible universe with which they agree and whose concept they determine. At the same time, they determine the concepts of all individual substances which ought to enter into this same universe. Everything, therefore, is in order even including miracles, although these latter are contrary to certain subordinate regulations or laws of nature. Thus, all human events cannot fail to happen as they have actually happened, supposing that the choice of Adam was made. But this is so, not so much because of the concept of the individual Adam, although this concept involves them, but because of the purposes of God, which also enter into this individual concept of Adam and determine the concept of the whole universe. These purposes determine, consequently, as well the concept of Adam as the concepts of all the other individual substances of this universe, because each individual substance expresses the whole universe, of which it is a part according to a certain relation, through the connection which there is between all things, and this connection is owing to the connection of the resolutions or plans of God.

I find that you bring forward another objection, Monsieur, which does not depend upon the consequences, apparently contradicting freedom, as was the objection which I just met, but which depends upon the matter itself and upon the idea which we have of an individual substance. Because, since I have the idea of an individual substance, that is to say of myself, it seems to you that we must seek what is meant by an individual concept in this idea and not in the way in which God conceives of individuals; and just as I have only to consult the specific concept of the sphere in order to decide if the number of feet in the diameter is not determined by this concept, in the same way you say I find clearly in the individual concept which I have of myself that I will be myself, in either case whether I make or do not make the journey which I intend.

In order to make my reply clear, I agree that the connection of events, although it is certain, is not necessary, and that I am at liberty either to make or not to make the journey, for, although it is involved in my concept that I will make it, it is also involved that I will make it freely. And there is nothing in me of all that can be conceived sub ratione generalitatis, whether of essence or of specific or incomplete concepts from which it can be deduced that I will make it necessarily. While, on the other hand, from the fact that I am a man, the conclusion can be drawn that I am capable of thinking, and consequently, if I do not make this journey, this will be against no eternal or necessary truth. Still, since it is certain that I will make it there must be indeed some connection between the me which is the subject, and the carrying out of the journey, which is the predicate. The concept of the predicate is always in the subject of a true proposition. There is, therefore, an omission, if I do make it, which will destroy my individual or complete concept, or which would destroy what God conceives or conceived in regard to me even before resolving to create me. For this concept involves, sub ratione possibilitatis, the existences or the truths of fact or the decrees of God upon which the facts depend.

I agree, also, that in order to determine the concept of an individual substance it is good to consult that which I have of myself, as we must consult a specific concept of a sphere in order to determine its properties. Nevertheless, there is between the two cases a great difference, for the concept of myself in particular and of any other individual substance is infinitely more extensive and more difficult to understand than is a specific concept, such as a sphere, which is only incomplete and does not involve all the practically necessary circumstances to get at a particular sphere. It is not enough in order to understand what the me is that I am sensible of a subject which thinks, I must also conceive distinctly of all that which distinguishes me from other possible spirits and of this latter I have only a confused experience. Therefore, it is easy to determine that the number of feet in the diameter is not involved in the notion of the sphere in general, it is not so easy to determine certainly, although we can decide quite probably whether the voyage which I intend to make is involved in my concept; were it not so it would be as easy to be a prophet as to be a geometer. Nevertheless as experience is unable to make me recognize a great number of insensible things in the body in regard to which the general consideration of the nature of bodies and of movements might convince me; in the same way, although experience cannot make me feel all that is involved in my concept, I am able to recognize in general that everything which pertains to me is involved in it through the general consideration of an individual concept.

Surely since God can form and does actually form this complete concept which involves whatever is sufficient to give a reason for all the phenomena that happen to me, the concept is therefore possible. And this is the true complete concept of that which I call the me. It is in virtue of this concept that all my predicates pertain to me as to their subject. We are, therefore, able to prove it without mentioning God, except in so far as it is necessary to indicate my dependence. This truth is expressed more forcefully in deriving the concept which is being examined from the divine cognizance as its source. I grant that there are many things in the divine knowledge which we are unable to comprehend but it does not seem to me that we must needs go into them to solve our question. Besides, if, in the life of any person, and even in the whole universe anything went differently from what it has, nothing could prevent us from saying that it was another person or another possible universe which God had chosen. It would then be indeed another individual. There must then be some reason a priori independent of my existence why we may truly say that it was I who was at Paris and that it is still I and not another who am now in Germany and consequently it must be that the concept of myself unites or includes different conditions. Otherwise it could be said that it is not the same individual although it appears to be the same and in fact certain philosophers who have not understood sufficiently the nature of substance and of individual beings or of beings per se have thought that nothing remained actually the same. It is for this, among other reasons, that I have come to the conclusion that bodies would not be substances if they had only extension in them.

I think, Monsieur, that I have sufficiently met the difficulties regarding the principal proposition, but, as you have made in addition some important remarks in regard to certain incidental expressions, which I used, I will attempt to explain them also. I said that the presupposition from which all human events could be deduced, was not that of the creation of an undetermined Adam but of the creation of a certain Adam determined in all circumstances, selected out of an infinity of possible Adams. In regard to this you make two important remarks, the one against the plurality of Adams and the other against the reality of substances which are merely possible. In regard to the first point, you say with good reason that it is as little possible to think of several possible Adams, taking Adam for a particular nature, as to conceive of several me's. I agree, but in speaking of several Adams I do not take Adam for a determined individual but for a certain person conceived sub ratione generalitatis under the circumstances which appear to us to determine Adam as an individual but which do not actually determine him sufficiently. As if we should mean by Adam the first man, whom God set in a garden of pleasure whence he went out because of sin, and from whose side God fashioned a woman. All this would not sufficiently determine him and there might have been several Adams separately possible or several individuals to whom all that would apply. This is true, whatever finite number of predicates incapable of determining all the rest might be taken, but that which determines a certain Adam ought to involve absolutely all his predicates. And it is this complete concept which determines the particular individual. Besides, I am so far removed from a pluralistic conception of the same individual that I agree heartily with what St. Thomas has already taught with regard to intelligences and which I hold to be very general, namely, that it is not possible for two individuals to exist entirely alike or differing solo numero.

As regards the reality of substances merely possible, that is to say, which God will never create, you say, Monsieur, that you are very much inclined to believe that they are chimeras. To which I make no objection, if you mean, as I think, that they have no other reality than what comes to them in the divine understanding and in the active power of God. Nevertheless, you see by this, Monsieur, that we are obliged to have recourse to the divine knowledge and divine power in order to explain them well. I find very well founded that which you say afterwards, "That we never conceive of any substance merely as possible except under the idea of a particular one (or through the ideas understood in a particular one) of those which God has created." You say also, "We imagine that, before creating the world, God looked over an infinity of possible things out of which he chose certain ones and rejected the others, certain possible Adams (first men), each with a great sequence of personages with whom he has an intrinsic connection; and we suppose that the connection of all these other things with one of these possible Adams (first men) is wholly similar to that which the actually created Adam had with all his posterity. This makes us think that it is this one of all the possible Adams which God has chosen and that he did not wish any of the others." In this you seem to recognize that those ideas, which I acknowledge to be mine (provided that the plurality of Adams and their possibilities is understood according to the explanation which I have given and that all this is understood according to our manner of conceiving any order in the thoughts or the operations which we attribute to God), enter naturally enough into the mind when we think a little about this matter, and indeed cannot be avoided; and perhaps they have been displeasing to you, only because you supposed that it was impossible to reconcile the intrinsic connection which there would be, with the free decrees of God. All that is actual can be conceived as possible and if the actual Adam will have in time a certain posterity we cannot deny this same predicate to this Adam conceived as possible, inasmuch as you grant that God sees in him all these predicates when he determines to create him. They therefore pertain to him. And I do not see how what you say regarding the reality of possibles could be contrary to it. In order to call anything possible it is enough that we are able to form a notion of it when it is only in the divine understanding, which is, so to speak, the region of possible realities. Thus, in speaking of possibles, I am satisfied if veritable propositions can be formed concerning them. Just as we might judge, for example, that a perfect square does not imply contradiction, although there has never been a perfect square in the world, and if one tried to reject absolutely these pure possibles he would destroy contingency and liberty. For if there was nothing possible except what God has actually created, whatever God created would be necessary and God, desiring to create anything would be able to create that alone without having any freedom of choice.

All this makes me hope (after the explanations which I have given and for which I have always added reasons so that you might see that these were not evasions contrived to elude your objections), that at the end your thoughts will not be so far removed from mine as they appeared to be at first. You approve the inter-connection of God's resolutions; you recognize that my principal proposition is certain in the sense which I have given to it in my reply; you have doubted only whether I made the connection independent of the free decrees of God, and this with good reason you found hard to understand. But I have shown that the connection does depend in my opinion upon the decree and that it is not necessary, although it is intrinsic. You have insisted upon the difficulties which there would be in saying, "If I do not make the journey, which I am about to make, I will not be myself," and I have explained how one might either say it or not. Finally, I have given a decisive reason which, in my opinion, takes the place of a demonstration; this is, that always in every affirmative proposition whether veritable, necessary or contingent, universal or singular, the concept of the predicate is comprised in some sort in that of the subject. Either the predicate is in the subject or else I do not know what truth is.

Now, I do not ask for any more connection here than what is found a parte rei between the terms of a true proposition, and it is only in this sense that I say that the concept of an individual substance involves all of its changes and all its relations, even those which are commonly called extrinsic (that is to say, which pertain to it only by virtue of the general inter-connection of things, and in so far as it expresses the whole universe in its own way), since "there must always be some foundation for the connection of the terms of a proposition and this is found in their concepts." This is my fundamental principle, which I think all philosophers ought to agree to, and one of whose corollaries is that commonly accepted axiom: that nothing happens without a reason which can be given why the thing turned out so rather than otherwise. This reason, however, often produces its effects without necessitation. A perfect indifference is a chimerical or incomplete supposition. It has seemed that from the principle above mentioned I draw surprising consequences but the surprise is only because people are not sufficiently in the habit of following out perfectly evident lines of thought.

The proposition which was the occasion of all this discussion is very important and should be clearly established, for from it follows that every individual substance expresses the whole universe according to its way and under a certain aspect, or, so to speak, according to the point of view from which it is regarded; and that a succeeding condition is a consequence, whether free or contingent, of its preceding state as though only God and itself were in the world. Thus every individual substance or complete being is, as it were, a world apart, independent of everything else excepting God. There is no argument so cogent not only in demonstrating, the indestructibility of the soul, but also in showing that it always preserves in its nature traces of all its preceding states with a practical remembrance which can always be aroused, since it has the consciousness of or knows in itself what each one calls his me. This renders it open to moral qualities, to chastisement and to recompense even after this life, for immortality without remembrance would be of no value. This independence however does not prevent the inter-activity of substances among themselves, for, as all created substances are a continual production of the same sovereign Being according to the same designs and express the same universe or the same phenomena, they agree with one another exactly; and this enables us to say that one acts upon another because the one expresses more distinctly than the other the cause or reason for the changes,- somewhat as we attribute motion rather to a ship than to the whole sea; and this with reason, although, if we should speak abstractly, another hypothesis of motion could be maintained, that is to say, the motion in itself and abstracted from the cause could be considered as something relative. It is thus, it seems to me, that the interactivities of created substances among themselves must be understood, and not as though there were a real physical influence or dependence. The latter idea can never be distinctly conceived of. This is why, when the question of the union of the soul and the body, or of action and of passion of one spirit with regard to another created thing, comes into question, many have felt obliged to grant that their immediate influence one upon another is inconceivable. Nevertheless, the hypothesis of occasional causes is not satisfactory, it seems to me, to a philosopher, because it introduces a sort of continuous miracle as though God at every moment was changing the laws of bodies on the occasions when minds had thoughts, or was changing the regular course of the thinking of the soul by exciting in it other thoughts on the occasion of a bodily movement; and in general as though God was interfering otherwise for the ordinary events of life than in preserving each substance in its course and in the laws established for it. Only the hypothesis of the concomitance or the agreement of substances among themselves therefore is able to explain these things in a manner wholly conceivable and worthy of God. And as this hypothesis alone is demonstrative and inevitable in my opinion, according to the proposition which we have just established, it seems also that it agrees better with the freedom of reasonable creatures than the hypothesis of impressions or of occasional causes. God created the soul from the very start in such a manner that for the ordinary events it has no need of these interventions, and whatever happens to the soul comes from its own being, without any necessity, on its part, of accommodation in the sequence of events to the body, any more than there is of the body's accommodating itself to the soul. Each one follows its laws, the one acts freely, the other without choice, and they accord with one another in the same phenomena. The soul is nevertheless the form of its body, because it expresses the phenomena of all other bodies according to their relation to its own.

It may be surprising, perhaps, that I deny the action of one corporeal substance upon another, when this seems so evident, but, besides the fact that others have already done this, we must also consider that it is rather a play of the imagination than a distinct conception. If the body is a substance and not a mere phenomenon, like a rainbow, nor a being, brought together by accident or by accumulation, like a pile of stones, its essence cannot consist in extension and we must necessarily conceive of something which is called substantial form and which corresponds in some sort to the soul. I have been convinced of this, as it were, in spite of myself, after having held a very different opinion before. But, however much I may approve of the Schoolmen in this general and, so to speak, metaphysical accounting for the basis of bodies, I also hold to the corpuscular theory as it is used in the explanation of particular phenomena, and for these latter nothing is gained by applying the terms, forms and qualities. Nature must always be explained mathematically and mechanically, provided it be kept in mind that the principles or the laws of mechanics and of force do not depend upon mathematical extension alone but have certain metaphysical causes.

After all this I think that now the propositions contained in the abstract which was sent to you will appear not only more intelligible but perhaps tenable and more important than might have been thought at first.