Sämtliche schriften und briefe series II, volume 3
Deutsche Akademie der Wissenschaften
pp 539-541

Date: 13/23 March 1699

Translated from the French

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[A II 3, p. 539]

     To Reverend Father Malebranche, father of the Oratory in Paris.

Hanover, 13/23 March 1699

     My Reverend Father,

     I have two reasons to write to you: one is to thank you for the honour of your remembrance, and the other is to congratulate you, or rather us, for the fact that the Royal Academy of Sciences will henceforth benefit from your insights,1 and that you will thus have more opportunities to contribute to the public good. Mathematicians need to be philosophers as much as philosophers need to be mathematicians: and you, my Reverend Father, who are both, and who is rightly considered one of the foremost philosophers of the age, are the most suitable person in the world to make this alliance.

[A II 3, p. 540]

     I wish I had brought the science of infinity as far as I wanted to, and as far as I think it can go, in order to satisfy your request.2 But there are things which need to be worked out, and there is no-one in this country who is involved with it, which puts me off. These kinds of studies, which are dry in themselves, become more agreeable when they can be shared with someone; and I am not in a position to work on calculations for long without assistance.
     As for your Treatise on the Communication of Motion,3 which you advised me you wanted to change:4 in saying that, I recognize both your penetration and your sincerity. One must be rather more penetrating to spot what needs to be changed in one's own work than to discover it in the work of others. But one has to be very sincere to acknowledge this, as you already have with regard to the laws of motion laid out in the Search after Truth, when you did me the honour of saying in your small treatise of 1692 that my reflections had given you the opportunity for your new reflections.5 Nevertheless, I still found something in this latest treatise which seemed to me to be subject to insurmountable difficulties, which prompted me to make some remarks about it;6 but I did not want to say anything about it for fear of passing as a man who takes it upon himself to contradict you. Now that you want to go over these things again, I am sending you these remarks for you to reflect upon as you see fit. You now agree with me that it is not the same quantity of absolute motion that is conserved, but the same direction, or as I call it the same quantity of direction. But I must nevertheless tell you that I think there is conserved also the same quantity not only of absolute force, but also of absolute motive action, which I have found completely different from what is called the quantity of motion; I reach this conclusion through an argument which surprised me all the more because it is easy and clear, and derived from the simplest notions, without supposing either weight or elasticity. And I have so many ways which all lead to the same end that Mr Bernoulli of Groningen, after looking into it, could not resist the force of the truth.7

[A II 3, p. 541]

     I would also be delighted to see your treatise on pure love one day. You always say profound things, and I have previously examined this matter when considering the principles of right, even giving definitions in the preface of the Diplomatic Code of People's Rights.9 In it, I say that to be just is to be charitable in a manner which conforms to wisdom. That wisdom is the science of happiness. That charity is a universal benevolence and benevolence is a habit of loving. That to love is the inclination which makes one find pleasure in the good, perfection, or happiness of others, or (which is the same thing) which makes the happiness of others enter into our own. And I add in the same place (before these disputes arose) that this definition helps to resolve a difficult problem, namely how love can be disinterested even though one never does anything unless inspired by one's own good. The fact is that our good is of the essence of love, but not our interest. That which pleases is a good in itself, and not a good of interest: it belongs to the end and not to the means. I even say there that divine love, or the pleasure one gets from what makes us feel the happiness and the supreme perfection of God, comprises so much of our true happiness that it makes it wholly complete. This also ensures that all the other loves and all the other pleasures are subordinate to the love of God, as they cannot otherwise give a solid pleasure, that is, a pleasure such as is needed for conspiring towards happiness, which is nothing other than the state of enduring joy. It then seemed to me that this was just about sufficient to resolve the difficulty. But when able men like you consider these things, they find material for a thousand fine reflections. I hope that you will continue to share yours with the public for a long time. And I am truly etc.


1. In 1699, Malebranche became an honorary member of the Royal Academy of Sciences.
2. See Malebranche's letter to Leibniz of 13 December 1698, A II 3, pp. 489-491. English translation available here.
3. Nicolas Malebranche, Des loix de la communication des mouvemens (Paris, 1692).
4. See Malebranche's letter to Leibniz of 13 December 1698, A II 3, pp. 489-491. English translation available here.
5. See the preface of Malebranche's Des loix de la communication des mouvemens.
6. Leibniz enclosed his remarks in a separate paper. See LH 4, 8, 3 Bl. 25.
7. See Johann Bernoulli's letter to Leibniz of 18/28 January 1696, A III 6, 626-637.
8. Nicolas Malebranche, Traittè de l'Amour de Dieu (Lyon, 1697).
9. 'Preface to the Diplomatic Code of People's Rights' (1693), in A IV 5, pp. 48-79. Partial English translation in SLT 149-152.

© Lloyd Strickland 2004. Revised 2016