Authoritarian ethics and subjectivist ethics
Because of the past influence of religion in our culture, many people (even some atheists) find it plausible to suppose that moral philosophy will have to be based on religious or theistic propositions. (It is worth noticing, though, that the ancient Greek philosophers never saw much need to base moral philosophy on religious beliefs, and most modern moral philosophers have not done so.)
How could morality be ‘based on’ religion? Not every way in which religious or theistic propositions might be relevant to moral thinking amounts to basing moral philosophy on such propositions. In particular, the following three claims, even if true, would not show that moral philosophy has to be based on religion. Consider, first: (1) God’s threats of punishment (or perhaps one’s belief in them)
provide a strong (even if somewhat crass) motive for being moral.