"A crippled man, however, does not cease to be a man. Spiritual obscurantists, or anithumanistic utilitarians, are not animals; they continue to function as humans. Still, they can no longer solve human problems rationally, or on the basis of the spiritual experiences the possession of which characterizes mature man. Hence there appear the curious transpositions of the problems of mature Western civilization to the new level of utilitarian immaturity." -- "Positivism and Its Antecedents"
I just saw a very good example of this: Peter Singer spoke to a colloquium I attend at NYU. He argued that utilitarian ethics would make it mandatory for, say, a surgeon to, on occasion, deliberately kill a (mostly) healthy patient under the knife in order to harvest his organs for several other patients who need them. I think his demonstration was sound, but, of course, Singer, being an anithumanistic utilitarian, thought this was a good argument for occasionally doing just this, rather than a crushing refutation of utilitarian ethics!