Full Idea
A 'moment' is something which is founded on something else. Examples are legion: smiles, headaches, gestures, skids, collisions, fights, thought, all founded on their participants, the continuants involved in them.
Gist of Idea
Moments are things like smiles or skids, which are founded on other things
Source
Peter Simons (Parts [1987], 8.4)
Book Reference
Simons,Peter: 'Parts: a Study in Ontology' [OUP 1987], p.304
A Reaction
The idea of a 'moment' and 'foundation' come from Husserl Log. Inv. 3. Simons says moments 'have a bright future in ontology'. It would be better if fewer of his examples involved human beings and their perceptions.