In previous entries I spoke of objective evil but failed to make very clear what it means for evil to be objectively real. To this task of clarification I now turn. To give credit where credit is due, I have been helped by Geoffrey Sayre-McCord's introduction to
Essays on Moral Realism, ed. Sayre-McCord, Cornell UP, 1988, pp. 1-23. But what follows is my own take on the matter.
Let's think about sentences like
1. Slavery is a great moral evil.
(1) is a grammatically indicative sentence that appears to predicate the property of being evil of an action-type or an institution-type. If it puzzles you how an action-type can be evil, I say: an action-type is evil just in case actual or possible tokens (instances) of the type are evil.
But is (1) a fact-stating piece of discourse? If yes, then it has a truth-value. But note that if sentences like (1) are truth-valued, it does not follow that some are true and others false. It might be that they are all false, as on J. L. Mackie's Error Theory. Now let's introduce some terminology.
TERMINOLOGY AND DISTINCTIONS
Cognitivist: One who maintains that sentences like (1) are either true or false.
Moral Realist: A cognitivist who maintains that some sentences like (1) are true and others false. For the moral realist, there are moral facts. Thus, if sentences like (1) are true, then there are moral facts that make them true.
Subjectivist: A cognitivist who thinks that the truth-maker of a moral claim is a fact about an individual's mind. On this view, what makes 'Slavery is evil' true is a fact about some individual's mind, for example, the fact that Lincoln feels slavery to be repugnant. This implies that moral claims of the form 'A is good/evil' are elliptical for claims of the form 'A is good/evil-for-X.' For the subjectivist, then, it is objectively true that slavery is wrong-for-X and there is an objective moral fact that makes it true; it is just that this fact is X's being in a certain state.
What makes subjectivism subjective is that it allows that what is good/evil for one subject may not be good/evil for another. If subjectivism is true, and I am an abolitionist who is repelled by the thought of slavery, but you are a Southern slave-holder who feels no repugnance at the thought of slavery and desires to own slaves, then our respective moral judgments, despite their objective truth-makers, do not conflict. It is easy to see that 'Slavery is wrong-for-me' and 'Slavery is not wrong-for-you' are not logical contradictories. Thus they can both be true.
It is important to realize that moral subjectivism as here defined does not imply alethic relativism, relativism about truth. Don't confuse 'It is true that slavery is wrong-for-Abe' with 'It is true-for-Abe that slavery is wrong.' What the moral subjectivist is maintaining is that moral claims, if true, are objectively true; but what makes them true are the subjective states of some person, states of desire, aversion, preference, and the like.
Intersubjectivist: A cognitivist who holds that the truth-maker of a moral claim is a fact about the practices and conventions of groups of people. Thus the truth-maker of 'It is wrong to eat human flesh' is the fact that we in our society do not do such a thing. This implies that moral claims of the form 'It is wrong to do A' are elliptical for claims of the form 'It is wrong-for-the-members-of-group-X to do A.'
Objectivist: A cognitivist who maintains that the facts that make-true moral claims are not facts involving the desires, aversions, preferences, goals, etc. of individual minds, nor facts involving the practices and conventions of groups. For the objectivist, we value kindness because kindness is good; it is not good because we value it. The good is not good because it satisfies desire, need, wish, or will; it satisfies because it is good. The evil is not evil because it thwarts desire, etc.; it thwarts desire, tc. because it is evil. Thus for the objectivist, kindness is good and cruelty is evil, objectively, intrinsically, i.e., not in relation to individuals or groups of individuals. Slavery is wrong in and of itself regardless of the going practices in a given society and regardless of anyone's desires or aversions.
Suppose you happen upon a defenceless person under physical assault by a much stronger person. If you are a moral objectivist, you will perceive the state of affairs as one that objectively ought not be, and will maintain that the ought-not-be-ness is what it is quite apart from social practices and conventions and individual desires and aversions.
Noncognitivist: One who denies that sentences like (1) have truth-values, and thus denies that there are moral facts as their truth-makers. The noncognitivist is a sort of instrumentalist about moral language. The moral instrumentalist denies that when we employ moral language we are ascribing moral properties to actions, state of affairs, people, or institutions. What we are doing is essentially practical, not theoretical. When I say that slavery is wrong I am attempting to change your attitude to it, or trying to persuade you to work towards its eradication.
Emotivist: A noncognitivist who holds that moral language is not fact-stating but expressive of feeling. Thus one who utters (1) expresses his disapprobation or repugnance.
Prescriptivist: A noncognitivist for whom moral claims such as (1) are essentially commands, while denying that commands have any ontological backing. A prescriptivist who says that abortion is wrong is not predicating a moral property of abortion; he is prescribing that one not commit abortion or permit them to be performed or do anything that encourages or supports their performance.
APPLICATION TO THE GOD PROBLEM
If evil is to bear upon the existence/nonexistence of God, then evil must be objectively real. But evil cannot be objectively real if noncognitivism is true. And it cannot be objectively real if subjectivism or intersubjectivism — forms of cognitivism — are true. For evil to be objectively real and to be relevant to the existence/nonexistence of God, objectivism as explained above must be true.
Now suppose you are an atheist who rejects objectivism. Even if you were to construct a sound argument from objective evil to the nonexistence of God, that argument could be of no use to you in justifying your belief that God does not exist. And this for the simple reason that you deny objectivism.