  Is there another way we might explain the fact of moral disagreement without conceding the impossibility of moral knowledge? Any theory that implies that moral knowledge is possible must face this question, but in general a range of considerations is available that might provide an alternative explanation depending on the nature of the disagreement.  They divide into three kinds: (a) disagreements about non-moral facts, (b) factors that distort judgment, and (c) disagreements about certain complex empirical facts that are also moral facts. In the first category are disagreements about religious facts, such as whether God exists. We will consider below the relevance of theology to moral epistemology. For the present it is sufficient to note that people with deep moral disagreements, say regarding abortion, euthanasia, and capital punishment, may have different religious views. To the extent that these can be considered non-moral views, for example, that God’s will is unambiguously expressed in the Bible, these differences may be able to explain the moral disagreement. Moreover, if it is possible to know whether these non-moral views are true, then we may be able explain moral disagreement without conceding the impossibility of moral knowledge. Other kinds of disagreements also fall into category (a). People with different moral outlooks frequently disagree about the psychological nature of humans and other animals or about large-scale economic and social theories relevant to assessing the consequences of economic and social policy. Disagreements about these difficult non-moral questions, assuming that these are issues about which objective knowledge is possible, could explain the absence of moral agreement. Unless these explanations can be eliminated, the inference from persistent moral disagreement to the impossibility of moral knowledge is on shaky ground. In category (b) we can place such things as having personal bias because of the implications of the issue at hand, being in the grip of a social ideology, and feeling abnormally depressed or fearful. A person, for example, who faces the death penalty for a crime, or someone who has strong feelings of vengeance, may not be able to form an objective view of the morality of capital punishment. Again we have a possible alternative way to explain moral disagreement. Finally, in category (c), if moral facts are extremely complex empirical facts (see the discussion of moral naturalism below), it is possible for moral disagreement to persist for the same reason that disagreement over complex scientific questions can persist.(For further discussion regarding moral disagreement see Miller 1992. For recent empirical work suggesting that moral disagreement cannot be explained away by one of the above means, see Doris and Plakias 2008.)