XXII: Count Ernst von Hessen-Rheinfels to Leibniz

My dear M. Leibniz:

There is reason for saying what M. Arnauld has said; for even if there were thousands among the Protestants who did not know their right hand from their left, who, in comparison with the savants, would be reputed as unthinking brutes, and who adhered only materially to heresy, certainly this cannot be said of you who have so much enlightenment, and with respect to whom, if there had never been any other but myself, as much as possible has been done to make you come forth from the Schismatics and to represent to you whatever there was to be represented. To mention merely one out of a thousand points; do you believe that Christ would have so constituted his Church that what one thought white another might think black, and that he would have constituted the ecclesiastical ministry in such a contradictory fashion that we should be in debate about it with the Protestants, we thinking one thing and you thinking another? For example, we hold that your ministers are laymen and are usurpers in the ministry. I do not know what you may think of ours who are so opposed to yours on this point. O, my dear M. Leibniz, do not lose thus the time of grace and hodie si vocem Domini auderitis, nolite obdurare corda vestra. Christ and Belial can no more agree together than do the Catholics and Protestants, and I know nothing which promises your salvation unless you become a Catholic.

XXIII: Leibniz to Arnauld

October 6, 1687.

As I always hold in high esteem your criticism when you have seen the point at issue, I will try this time so to write that the positions which I hold as important and almost as certain, may appear to you, if not certain, at least as entertainable; for it does not seem to me at all difficult to answer the doubts which you still have, and which, in my opinion, result only because a person, however able he may be, when he has his mind made up and is otherwise diverted, has difficulty at first in entering into a new line of thought upon an abstract subject, where neither figures nor models nor illustrations can assist him.

I have said that the soul naturally expresses the whole universe in a particular sense and according to the relation which other bodies have to its own; consequently, as it expresses most directly that which belongs to the parts of its own bodies, it ought, in virtue of the laws of relationship which are essential to it, to express in particular certain unusual changes of its own body; for instance, that which happens when it feels pain. To this you reply that you have no clear idea of what I mean by the word express; that, if I mean by it a thought, you will not agree that the soul has any more thought and cognizance of the movement of the lymph in the lymphatic ducts than of the movements of the satellites of Saturn. If I mean, however, something else, you say you do not know what it is, and, consequently (supposing that I were not able to explain it distinctly), this word would be of no service in letting us know how the soul can become aware of the feeling of pain, since it would needs be, you say, that it already knew that I was being pricked instead of obtaining this knowledge only by the pain which it felt.

In reply to this I will explain this word which you think is obscure, and I will apply it to the difficulty which you have raised. One thing expresses another, in my use of the term, when there is a constant and regulated relation between what can be said of the one and of the other. It is thus that a projection in perspective expresses a structure. Expression is common to all forms, and is a class of which ordinary perception, animal feeling and intellectual knowledge are species. In ordinary perception and in feeling it is enough that what is divisible and material and what is found common to several beings should be expressed or represented in a single indivisible being, or in the substance which is endowed with a true unity. We cannot at all doubt the possibility of such a representation of several things in a single one, since our own souls furnish us examples; this representation, however, is accompanied by consciousness in a rational soul and becomes then what is called thought.