Full Idea
Logic is reductionist not accidentally, but essentially and necessarily: following the route marked out by Frege and Russell, it wants to turn the concept into a function (...when actually a concept is a form, or a force).
Gist of Idea
The logical attitude tries to turn concepts into functions, when they are really forms or forces
Source
G Deleuze / F Guattari (What is Philosophy? [1991], 2.6)
Book Reference
Deleuze/Guattari: 'What is Philosophy?' [Verso 1994], p.135
A Reaction
[Last part on p.144] I'm not sure that I understand 'form or force', but the idea that concepts are mere functions is like describing something as 'transport', without saying whether it is bus/bike/train.. Is a concept a vision, or a tool?