Bernard Williams (2005). In the Beginning Was the Deed: Realism and Moralism in Political Argument. (p.48)

[R]ationality itself requires ethical thought to be systematized…, is baseless; so far from trying to eliminate or reduce all “think” concepts in the name of rationality, we should try to hold on to as many as we can…

…The familiar (originally Hegelian) criticism of modern ethical reflection that it is too abstract and theoretical to provide any substance to ethical life is well taken, and it is precisely the use of “thick” ethical concepts, among other things, that contributes to a more substantive type of personal ethical experience than theory is likely to produce.

Bernard Williams (2005) Modernity and the Substance of Ethical Life. In In the Beginning Was the Deed: Realism and Moralism in Political Argument. (p.48)