Full Idea
My own view is that moral justification must be capable of motivating, but not in virtue of reliance on pre-moral motives.
Gist of Idea
Morality must be motivating, and not because of pre-moral motives
Source
Thomas Nagel (Equality and Partiality [1991], Ch.5)
Book Reference
Nagel,Thomas: 'Equality and Partiality' [OUP 1995], p.45
A Reaction
This may well be the core and essence of Kantian moral theory. I'm inclined to think of it as 'Kant's dream', which is of ultra-rational beings who are driven by pure rationality as a motivator. People who fit this bill tend to be academics.