TITLE: Why "integralis" over "summatorius"?
QUESTION [13 upvotes]: It is written that Johann Bernoulli suggested to Leibniz that he (Leibniz) change the name of his calculus from "calculus summatorius" to "calculus integralis", but I cannot find their correspondence wherein Bernoulli explains why he thinks "integralis" is preferable to "summatorius." Can someone enlighten me? Thank you.

REPLY [5 votes]: Bernoulli writes this to Leibniz in 20/30 April 1695. His justification for this choice of words is that "differentials are part of a whole" ("integer" being Latin for whole).
Leibniz replies (6/16 May 1695) that this appellation does not displease him, but that he considers his preferred term "sum" more illuminating and closer to the source of the notion.
See the Akademie-Ausgabe, III6A, pp. 348, 356:
http://www.leibniz-edition.de/Baende/ReiheIII.htm