You say, M., that "those who hold to the hypothesis of occasional causes, saying that my will is the occasional cause, while God is the real cause of the movement of my arm, do not claim that God does this at the moment by a new volition, which he has each time I wish to lift my arm, but through that single act of eternal will, by which he resolved to do everything which he foresaw would be necessary for him to do." To this I reply that we can say with the same reasoning, that miracles also are not the result of a new act of will on God's part, being conformable to a general plan; and I have already stated, in what precedes, that every act of will on God's part involves all the others, but with a certain order of priority; if I properly understand the position of the authors of occasional causes, they introduce a miracle which is not less miraculous for being continual, for it seems to me that infrequency does not constitute the conception of miracle. It will be said that God acts in that, only according to a general rule and consequently without miracle, but I do not grant this consequence and I think that God could make general rules with regard to the miracles themselves. For instance, if God resolved to give his grace immediately, or to perform some other action of this nature every time that a certain condition came about, this action would, nevertheless, be a miracle although quite in the ordinary. I confess that the authors of occasional causes can give another definition of the term, but it seems that according to usage a miracle differs internally and substantially from that which results from ordinary activity, and its distinctiveness does not depend upon its unusualness; properly speaking, God performs a miracle when he does anything which surpasses the powers which he has given to created things and which he maintains in them; for example, if God should make a body, which was put in circular motion by means of a sling, to go on freely in a circular line even when it was released from the attachment, this, when it was neither pushed nor retained by anything, would be a miracle, for, according to the laws of Nature the body should travel along the line of the tangent: if, moreover, God should decide that such should always be the case, he would perform a natural miracle, for this movement could not be explained by anything more simple. In the same way, we should have to say in accordance with the current conception, that if the continuation of the motion were beyond the power of bodies, the continuation of the motion would be a true miracle; while my position is that the corporeal substance has the power to continue its changes according to the laws which God has put into its nature and which he maintains there.

To make myself better understood I will add that the activities of the mind change nothing at all in the nature of the body, nor the body in that of the mind; and I will also add that neither does God change anything on the occasion of their action except when he performs a miracle. In my opinion, things are so concerted together that the mind never desires anything efficaciously excepting when the body is ready to accomplish it in virtue of its own laws and forces; while, according to the authors of occasional causes, God changes the laws of the body on the occasion of the action of the soul and, vice versa. That is the essential difference between our positions. Therefore, we should not ask how the soul can give any motion or new determination to the animal spirits, since it never does anything of the kind, for there is no interaction between spirit and body, and there is nothing which can determine what degree of velocity a mind will give to a body, nor what degree of velocity God may be minded to give to the body on the occasion of the mind's action according to a certain law. The same difficulty is found with regard to the hypothesis of occasional causes which there is in the hypothesis of a real influence of the soul upon the body and vice versa; because we can see no relation or basis for such a rule. If one were to say, as M. Descartes seems to, that the soul, or God on the occasion of its acting, changes merely the direction or determination of the motion and not the force which is in bodies, (since it does not seem probable to him that God would interrupt at each moment on the occasion of the willing of spirits, this general law of nature, namely, that the same force should perdure), I would reply that it will be quite difficult to explain what connection there can be between the thoughts of the soul and the sides or the angles of direction of bodies, and furthermore that there is in nature another general law which M. Descartes has not perceived but which is, nevertheless, important- namely, that the sum total of the determinations or directions must always perdure. For I find that if any straight line be drawn, for example, from east to west, through a given point, and if all the directions of all the bodies in the world in so far as they advance toward or move away in lines parallel to this line be calculated, the difference between the sums of the quantities of all the easterly directions and of all the westerly directions will ever be found the same, whether certain particular bodies which might alone be supposed to have relations among themselves, be regarded or whether the whole universe be regarded. In this latter case the difference is always zero. Everything is perfectly balanced and the easterly and westerly directions in the universe are exactly equal. If God wished to do anything against this principle it would be a miracle.