Full Idea
We do not claim, as some do, that fundamental dispositional properties are the ontological basis of all properties. On the contrary, there are equally fundamental categorical properties - for example, spatio-temporal relations and structures.
Gist of Idea
The ontological fundamentals are dispositions, and also categorical (spatio-temporal and structural) properties
Source
Brian Ellis (Scientific Essentialism [2001], 3.09)
Book Reference
Ellis,Brian: 'Scientific Essentialism' [CUP 2007], p.127
A Reaction
The source of disagreement between Bird and Ellis. Bird denies the existence of 'categorical properties'. I think I am with Bird. Space and time are as much part of the given as the elements, and then categorical properties result from dispositions.