Full Idea
In the beginning the field concept was no more than a means of facilitating the understanding of phenomena. ...In the new field language it is the field and not the charges themselves which is essential. The substance was overshadowed by the field.
Gist of Idea
The concept of a field gradually replaced the substances in explaining relations between charges
Source
Einstein,A/Infeld,L (The Evolution of Physics [1938], p.151), quoted by Penelope Maddy - Naturalism in Mathematics II.4
Book Reference
Maddy,Penelope: 'Naturalism in Mathematics' [OUP 2000], p.115
A Reaction
This is very important for philosophical metaphysicians, especially those like me who want to explain the universe by the nature of the stuff that composes it. The 'stuff' had better not be simplistic individual 'substances'.