The use of RESSORT in L’Esprit des lois

There are 25 instances of the word ressort in L’Esprit des lois, the first being this: “Mais dans un Etat populaire il faut un ressort de plus, qui est la Vertu.” [III, 3]. Now as it happens, this sentence also contains the first occurrence of vertu (of 175), save one in the preface (“C’est en cherchant à instruire les hommes que l’on peut pratiquer cette vertu générale qui comprend l’amour de tous.”). Curiously, both words are addressed, though the ostensible topic is vertu, in the short Avertissement de l’auteur which was added in the editions of 1757 and 1758 (In my translation The Spirit of Law, based on the edition of 1750, it appears only in annex). There the word vertu is used 13 times in order to conclude that in revising the text, “in most places where I have used the word virtue, I have put political virtue.” This, clearly enough, to avoid too Christian a reading of a word which to the Romans (and to Montesquieu) meant something quite different from primness and chastity.
Nevertheless, he takes advantage of the same Avertissement to clarify somewhat the meaning of ressort, in the process using it six times. The problem he sees is curiously very different from the one I wish to raise, and while the latter pertains specifically to the way the word is to be rendered in English, Montesquieu’s own commentary is not without interest, particularly since in the process he illustrates the double use of the word and thus exemplifies the very dilemma which I myself wanted to address.
It is not until III, 10 that the author actually gets around to applying his notion of governmental ressort by affirming that the ressort of monarchical government is honor. The word comes out as “spring” in the two translations so far of L’Esprit des lois, though it makes no sense. But if Montesquieu brings it up, and right at the start, in what was to stand for centuries as the definitive edition, it is because he has already encountered a difficulty with French readers who have misread ressort as meaning not merely the underlying principle but also the entire essence of a given form of government. So he want to explain that the ressort of one government may all the same be to some degree present in another, of which is it nonetheless not the ressort. In the process, he brings in precisely the notion of a spring to illustrate what he is and is not intending:

[…] It is important to remember that there is a very great difference between saying that a certain quality, modification of spirit, or virtue, is not the ressort that makes a government act, and saying that it is not present in that government. If I were to say that a certain wheel or cog are not the ressort that makes the watch run, would one conclude that they are not present in the watch? So far from it being true that moral and Christian virtues are excluded from monarchy, that even political virtue is not. In a word, honor is present in the republic, although political virtue is its ressort; political virtue is present in monarchy, although honor is its ressort.

In only the second of these four occurrences of ressort in the same paragraph is “spring” the correct equivalent. The others are a metaphorical extension but one which is fully incorporated into the daily language, as is shown by the continuing definitions and their examples in Antoine Furetière’s dictionary of 1690:

RESSORT is also said for unknown causes by which nature acts. The life of animals is maintained by secret and marvelous ressorts. Nature has unimaginable ressorts for producing all the surprising effects we see.
RESSORT is said figuratively in spiritual and moral matters. No one must perceive the ressorts of Providence. A politician activates many a ressort and cooks up a thousand intrigues to win or preserve the alliance of neighboring princes. An engineer brings into play all the ressorts of his mind, tenses all its ressorts to invent some new machine or problem.

The last instance here shows how easy it is to move between the levels of meaning, so that an instance of “literal” meaning can be invoked in the same sentence to illustrate the supposedly secondary meaning. Indeed ressort applied to the mind is not necessarily entirely metaphorical; it might just suggest something about how, at some level or by some system of understanding, the mind works. Still, it is noteworthy that not until this late Avertissement had Montesquieu tied the ressort metaphor by analogy to a mechanical spring.
It is just this metaphorical sense that is lacking in the English word “spring,” and why deciding once and for all that ressort must be faithfully translated “spring,” as previous translators have done, can only obscure the majority of instances where the meaning is quite other.
The mechanical meaning of ressort, we are told by the same lexicographer, is primarily associated with watches and automata, both of which are great objects of public attention in this time frame. Even a metaphorical use of the word may turn mechanical; there are several instances in The Spirit of Law of expressions like “tendre tous les ressorts” (not infrequently, as here, with ressorts in the plural) which draw at least partly on the image of springs, notably in combination with verbs like tendre and relâcher. Montesquieu does, as we have already seen, occasionally have recourse (about a half-dozen times) to the analogy of a watch spring or the implicit analogy of a robotic machine; in every other instance, ressort calls for some other kind of linguistic treatment.
For the time being, I first in most cases translated ressort as “energy” or “energy source,” but not of course in those cases where it refers to jurisdiction (related to the verb ressortir). It would have been tempting to use “motive” or “motivation” except that the word motif is not uncommon elsewhere in the text. The same goes for “principle”.  Then it came to me that in a number of passages the meaning seemed to be something like “resource”, and I have experimented with that term in the most recent iteration.

One curious passage which did not seem to fit with the others was this :  “C’est un grand ressort des Gouvernemens modérés que les lettres de grace.” (VI, 16). None of the equivalents attempted previously seemed apt here. When I decided that the idea here was more like “resource”, I also realized that the same word might work in other contexts. So now “resource” is the word most used, not for any supposed etymological affinity between the words, but just because the gist seemed to work.

Another thought: perhaps ressort is one of those problems that could benefit from a noun-verb switch. I will experiment some. Suppose the monarchical government were “powered by” honor?