Corpore cadente . . . : Historians Discuss Newton’s Second Law

For about the last thirty years Newton scholars have carried on a discussion on the meaning of Newton’s second law and its place in the stucture of his physics. E. J. Dijksterhuis, Brian D. Ellis, R. G. A. Dolby, I. Bernard Cohen, and R. S. Westfall in their treatments of these matters all quote a passage that Newton added to the third edition of the Principia. This passage, beginning “Corpore cadente” (“when a body is falling”), was inserted into the Scholium following the Laws. The present article is an analysis of the literature that treats this passage and its relation to the second law. The conclusion is that they are right who see a deep duality in Newton’s mind regarding this law.