The argument, as straightforwardly put by the Stanford Encyclopaedia of Philosophy:
1. Moral facts exist.
2. Moral facts have the properties of being objective and non-natural.
3. The best explanation of there being objective and non-natural moral facts is provided by theism.
4. Therefore the existence of moral facts provides good grounds for thinking theism is true.
Answer:
A common opinion of the religious is that a person can’t be good without God. This argument goes a step further and says that because we know what is good and right and what is wrong, there must be a God.
A more widely used name for a “moral fact” is a “moral absolute” or “absolute moral”. It’s a standing judgement that something is either right or wrong, no matter what. In practical terms, it is what it is regardless of what people think. It’s true anywhere in the world, at any time. It’s the moral equivalent of a logical axiom or a fundamental universal constant.
Since the existence of moral facts is the first premise, and the second premise depends on it, the whole thing hinges on whether they can actually be established. So how do apologists go about doing this? Most of the time, they point out moral judgements which nearly everyone agrees on, such as that murder, rape or an event like the Holocaust is/was bad and wrong.
This won’t do, because moral facts or absolutes as described in these arguments are supposed to be independent of human beings. They’re specific properties of the universe like the laws of physics or logic, written into it by a god. If every human being on Earth disagreed with one (from the religious perspective, if all of humanity turned against God), it would still stand. Therefore the true moral absolutes (if any) could be completely at odds with near-universal human opinions, and so the fact that there are near-universal human moral opinions doesn’t make them absolutes. It just means humans have things in common.
A blogger arguing for moral absolutes challenged me to come up with a reasonable way to see the Holocaust (among other horrible actions) as a good thing. The implication was that if I failed, our near-universal condemnation of the Holocaust had to be based on a moral absolute. That’s wrong, as I’ve just explained, but I took him up on it anyway. All I had to do to contradict him was step outside of the human race and consider the Holocaust from the perspective of ants, or termites. Fewer Jews in Germany meant more abandoned houses in the ghettos, so more food and living space for bugs of all kinds. The Holocaust was so obviously wrong to humans, but if it loses its tragedy when exclusively human concerns are ignored then that’s hardly an absolute.
Only humans are aware of having a stake in the moral and ethical parameters within which we live our lives. That’s why we’ve worked so hard to shape them over thousands of years, supporting one adjustment over another with various forms of authority from self-contained logic to force to claims of divine backing. It appears that we’ve done it all ourselves, completely independent and ignorant of what any true absolute moral facts might be.
– SmartLX
The Great Big Arguments #7: Morality
“Only humans are aware of having a stake in the moral and ethical parameters within which we live our lives. That’s why we’ve worked so hard to shape them over thousands of years, using various forms of authority from self-contained logic to force to claims of divine backing to support one adjustment over another.”