This article traces the impact of philosophical questions regarding the gro
unds of moral autonomy and heteronomy (rule-from-another as opposed to rule
-from-oneself) on classical sociological theory, arguing that both Weber an
d Durkheim understood sociology to have a contribution to make in the debat
e,with Kant over the grounds of ethical action. Both insisted that the only
possible ethical action was one within the bounds of rational knowledge th
at was inherently authoritative, but this sat uneasily with their focus on
the relation between concrete social authority and the authoritativeness of
beliefs in the sociology of religion. In rejecting Comte's explicit avowal
of the embodiment of moral authority in the secular priesthood of sociolog
ist, Weber and Durkheim had to paper over the social authority supporting t
he formulation of this rational knowledge. Each then produced a sociology o
f knowledge without a well-specified mechanism, in turn encouraging the dev
elopment of the sociology of knowledge as ct flawed sub-discipline.