  In the history of infinitesimal calculus, we trace innovation from Leibniz to
Cauchy and reaction from Berkeley to Mansion and beyond. We explore 19th
century infinitesimal lores, including the approaches of Simeon-Denis Poisson,
Gaspard-Gustave de Coriolis, and Jean-Nicolas Noel. We examine contrasting
historiographic approaches to such lores, in the work of Laugwitz, Schubring,
Spalt, and others, and address a recent critique by Archibald et al. We argue
that the element of contingency in this history is more prominent than many
modern historians seem willing to acknowledge.
