Cognitivism is the
meta-ethical view that ethical
sentences express
propositions and can therefore be
true or false (they are
truth-apt), which
noncognitivists deny. Cognitivism is so broad a thesis that it encompasses (among other views)
moral realism (which claims that ethical sentences express propositions about mind-independent facts of the world),
moral subjectivism (which claims that ethical sentences express propositions about peoples' attitudes or opinions), and
error theory (which claims that ethical sentences express propositions, but that they are all false, whatever their nature).