A puzzle that I will need to unravel at some point.
Journal of Sacred Literature
A very interesting idea (although one would wish for some sort of evidence to back it up). However, L'Hopital's book was not written by L'Hopital, but, it would seem, by Johann Bernoulli; it was a course, purchased from Bernoulli by L'Hopital under a very unusual contract, that was merely published under L'Hopital's name. L'Hopital and Bernoulli seem to have become acquainted by way of Malebranche, who interacted with a number of mathematicians and was a strong advocate of Leibniz's calculus, and a leader of the 'infinitesimalists' in the Academy of Sciences. The Analyse was the first significant textbook for the differential calculus; in substance it was largely Bernoulli's, with some revisions. So here's the puzzle. If that's the case, what room is there for Malebranche's editing? Presumably he could still have done the diagrams by hand; but what revisions, if at all, were due to him, and what to L'Hopital? And for each of these questions what's the actual state of the evidence? Is this really just a legend, a just-so story concocted on the basis of Malebranche's association with the great mathematicians of the time, or is there substance to it? And if there is substance to it, how much?