  Newton's basic ideas developed and evolved throughout his career and changed
in sometimes surprisingly profound ways. In this paper I propose an outline of
the evolution of Newton's conceptual framework by following the development of
his ideas throughout the early work preceding the first edition of the
Principia, and thus to complete the work that has been done by Whiteside and
Ruffner with respect to Newton's mechanics. I shall show that these evolutions
- the mechanical and the metaphysical - are closely interrelated. My focus will
be on a key text that marks a turning point both from the metaphysical and the
methodological point of view: the "De gravitatione et aequipondio fluidorum".
Rather than looking upon it as an isolated fact, I establish the connections of
this text to other manuscripts from the same period, primarily the manuscript
"Elements of Mechanicks" in the Hall & Hall edition, as well as the two
variants of the "De Motu", to which it can be said to relate as to a "zero
release".
