In “Miracle of Theism” Mackie discusses a few moral arguments for God’s existence, but opens with what is (to me, at least) an interesting statement. He acknowledges that such arguments may reinforce belief in God, but suggests that very few people believe due to such arguments.
This strikes me as odd because a form of the moral argument was instrumental in my own coming to believe in Christianity.
I think it is a very powerful argument, and it is interesting to see the difference between my own line of thought and Mackie’s.
And this begins almost right away. Mackie insists that, if one takes the conscience as a reliable source of information, one must deny that it points to anything beyond itself (to some kind of non-physical reality). Presumably, this is because a trustworthy conscience would be self-justifying, but this strikes me as completely wrong thinking. Really, it seems more like one of Oscar Wilde’s jokes than a serious point.
I can see it now: “Don’t worry about what your conscience tells you. If your conscience is right, it’ll still be right after you’ve changed it.”
I take it as self-evidently true that sensory experience is basically trustworthy (we’re not living in a dream-world), but this does not preclude the idea that such experience points to a real world beyond our sensations. Rather, it is precisely because we consider our senses to be valid sources of information that we accept the idea that there is an external world.
To say that the validity of the conscience somehow undermines the idea that there is an external reality to which it points, therefore, is to get things precisely backward. I don’t know how Mackie can conclude this, and he doesn’t tell us. Rather, he simply asserts this.
But he does close with a brief mention of the much more popular idea that morality can be described in terms of human social and biological history. But he fails to address the nearly as common reply that this completely misses the point.
Rather, this is simply a rejection of the idea that the conscience is a valid source of information. It explains how humans might have come to believe in morality, but denies, rather than explains, that the conscience is a trustworthy source of information. It is to deny objective morality altogether.
But what if that is simply the way things are? What if morality is subjective?
I have a long list of objections to this, but the first is the simple fact that this is based in an arbitrary approach to human experience. There is no less reason to trust that the conscience is reporting an external reality than to trust one’s senses. If one really believes what one experiences is evidence, one will accept them both.
But, if one wants to insist that the one is illusory while the other is giving us sober truth, then one needs to offer a reason for that.
And neither Mackie, nor the other philosophers I’ve read have ever been able to do this.