Full Idea
The assumption that shape and solidity are the fundamental mechanical qualities requires an implausible hypothesis of a substance or material filling the space of bodies.
Gist of Idea
The assumption that shape and solidity are fundamental implies dubious 'substance' in bodies
Source
Harré,R./Madden,E.H. (Causal Powers [1975], 9.II.B)
Book Reference
Harré,R/Madden,E.H.: 'Causal Powers: A Theory of Natural Necessity' [Blackwell 1975], p.172
A Reaction
This is 'substance' in the sense of matter, rather than in the sense of an Aristotelian essence. They defend fields (rather than particles) as the fundamentals of the physical world.