Full Idea
Most model theories abstract from reality in order to focus on the essential nature of some kind of process or system of relations. ... The point of idealizing in this case is not to simplify, but to eliminate what is not essential.
Gist of Idea
The point of models in theories is not to idealise, but to focus on what is essential
Source
Brian Ellis (Scientific Essentialism [2001], 4.03)
Book Reference
Ellis,Brian: 'Scientific Essentialism' [CUP 2007], p.153
A Reaction
I like this idea a lot. It is where scientific essentialism cashes out in actual scientific practice. Ellis's example is the idealised Carnot heat engine, which never can exist, but which captures what is essential about the process.