I. Versions and variants

Since the Paris manuscript BNF Fr. 12265 reveals many revision stages, it was crucial for the editors to make explicit the main stages of revision in structure and content made by Émilie Du Châtelet, through establishing them as textual versions on their own, rather than placing them in the variant apparatus. On the one hand, this makes it easier for the reader to perceive the differences by presenting the versions as distinct texts, so that the reader does not need to reconstruct all revision stages from the entries in the variant apparatus, which at times is quite a complicated task. On the other hand, in order to analyze the differences between the revision stages in detail, the reader needs to compare the online edited versions by arranging them in separate windows on the screen or display. This might be demanding at times, yet it is still easier than reconstructing all revision stages from the variant apparatus.

However, in order to make the comparison between the distinct versions easier, we decided to offer, in these introductory notes, a survey of some striking differences between the versions. We continue to provide a variant apparatus, however, representing the finer-grained revisions made by Émilie Du Châtelet.

By consequently establishing versions as texts on their own, and as distinguished by the amount of changes in structure and content, we also establish revision stages as variants which might only consist of one word being changed.

We have identified six revision stages in this chapter. There is an initial fair copy (siglum A), which then undergoes various revisions, leading to a final handwritten version (siglum D). In addition, there are the two published printed versions from 1740 and 1742 (sigla E and F).

Of the manuscipt revision stages, the fourth is established as a full version (siglum D). The earlier revision stages are available in the edition as variants.

VERSIONS AND VARIANTS	SOURCE
A = VARIANT DOCUMENTED IN THE VARIANT APPARATUS OF VERSION D	Émilie Du Châtelet: Institutions de physique, Bibliothèque nationale de France, MS fr. 12265, 218r–224r
B = VARIANT DOCUMENTED IN THE VARIANT APPARATUS OF VERSION D	Émilie Du Châtelet: Institutions de physique, Bibliothèque nationale de France, MS fr. 12265, 218r–224r
C = VARIANT DOCUMENTED IN THE VARIANT APPARATUS OF VERSION D	Émilie Du Châtelet: Institutions de physique, Bibliothèque nationale de France, MS fr. 12265, 218r–224r
D = MAIN TEXT = VERSION	Émilie Du Châtelet: Institutions de physique, Bibliothèque nationale de France, MS fr. 12265, 218r–224r
E = MAIN TEXT = VERSION	Émilie Du Châtelet: Institutions de physique, Paris: Prault, 1740, 243–254
F = VARIANT DOCUMENTED IN THE VARIANT APPARATUS OF VERSION E	Émilie Du Châtelet: Institutions physiques, Amsterdam: Au Depens de la Compagnie, 1742, 254–266.

II. Short survey of the main manuscript version D

This chapter undergoes relatively few revisions, both within the manuscript and in the printed versions. Much of the original fair copy (from variant A) is preserved in this version D. However, Du Châtelet reorders some sections as well as making some modest deletions and insertions.

III. Some significant differences between versions

One significant series of changes is the reordering of some sections. One case of this is a section advancing various concrete examples of composite motions in bodies, which appears relatively late (§ 290) in the first version of the manuscript, but is later moved earlier (to § 287), prior to some more theoretical discussions of composite motion.

Another important change concerns the justification of the famous ‘parallelogram rule’ for composing forces, in § 285. Version A stresses that the parallelogram method cannot be reversed: that is, from given composite force alone we cannot uniquely recover the forces composing it, “parcequ’on peut Bâtir une jnfinité de triangles sur une meme base.” Discussion of this point is deleted from later versions, however.

A third important change is that a new section (§ 293) is added in Du Châtelet’s own hand. This section concerns rotational motion, which is an important special case of composite motion, and presents special challenges for those (like Du Châtelet) who give a relationalist account of space.