Peter Singer, "Ethics Beyond Species and Beyond Instincts:  A Reply to Richard Posner" “I believe that ethical argument is and should be powerless against tenacious moral instincts”  -- Richard Posner Translation:  Don't listen to Peter Singer. ~ Examples of "tenacious moral instincts" (some are attitudes, some are principles) animals count little (or not at all) instinct to reciprocate all (white) men are created equal all people are created equal sex outside marriage dishonors your father there should be equal pay for equal work distrust of foreigners ~ Should ethical argument be powerless against all these ideas and tendencies?  Singer's approach:  first consider in what sense these things are moral or instinctive. moral instinct = a strong intuition that can be universalized; that is, you'd still have the intuition if you could make yourself perfectly impartial. (Why call an instinct moral if doesn't have this character?) moral instinct = innate, universal tendency explained by evolution.  An attitude that helped early hominids and humans survive, and therefore got passed down through the generations to us. Other possibilities, not considered by Singer: moral instinct = one of various innate ideas found in all people, but selectively reinforced by culture.  These ideas include compassion/harm, purity/pollution, hierarchy/respect, fairness/equality.    moral instinct = an intuition deeply ingrained in a culture as part of its core behavioral code. ~ Singer's argument-- If what you mean by moral instinct is #1, then yes, ethical argument is powerless against it. But then many items on the list are not moral instincts. If you mean #2 (or #3 or #4) there's no reason NOT to use ethical arguments to try to change people's minds.