Full Idea
For Newton, mass is central to matter.
Gist of Idea
Mass is central to matter
Source
report of Isaac Newton (Principia Mathematica [1687]) by William D. Hart - The Evolution of Logic 2
Book Reference
Hart,W.D.: 'The Evolution of Logic' [CUP 2010], p.38
A Reaction
On reading this, I realise that this is the concept of matter I have grown up with, one which makes it very hard to grasp what the Greeks were thinking of when they referred to matter [hule].