I'll take it you can't demonstrate that morals exist objectively.
But, you should make sure you differentiate between a "moral fact" as in "something that exists objectively, metaphysically in the absence of any consciousnesses" and "moral fact" as in "something we all (mostly) agree to". Good luck (chuckle...)
The problem is that we need to define terms. I would argue that there is no morality in the absence of any consciousness. When Christian theists say morality is objective, that is not what we mean. Objective Morality is independent of the human consciousness. It is objective with respect to those who live under it. It is true no matter the opinion of those living under it. As long as those who live under it decide what is right and wrong, then you have question as to what is right or wrong and who has the right to determine that. A "moral fact" dependent solely on what we agree on means nothing because we can't all agree - and never will. How do you know you are right and those you disagree with are wrong?
Without an objective standard, how do you know tell? Anderson is trying the old Atheist tactic to get out of the force of the moral argument for the existence of God by arguing that a morality that God is not subjected to is no absolute standard and morality without a consciousness is a logical contradiction. However this argument is truly silly. In order for morality to be objective for human being it merely has to be true independently of us. That morality is the standard by which we will be judged against by our maker whether or not we agree to be judged by that standard. That morality is based on God's character and by which He says. If we base morality on what most of us agree on then it's only relative with respect to one another.
Often times attempt to define morality apart from God lead to basing it one of four ideas or utilitarianism or some combination of them:
c. Respect for Autonomy
The problem is that even the most ardent skeptic admits his or her own finitude and being prone to making mistakes. Given this inescapable conclusion, why would anyone think they know what is best for any given person in any given situation? Or how would we know what justice is when often times we are merely blinded by our own self-interest? The "respect for autonomy" part really amuses me because where does it end and what does it mean? Does it end when one person's autonomy is misused to hurt others? Who decides when that is? What happens when you disagree?
It is an example of extreme hubris to think that just because we can't think of any reason why God would allow reality to work out as it has that there isn't a reason. That is arguing in the gaps of your ignorance. God is not subjected to Morality. How can you be limited by what you have decreed? There is no dilemma. here. IF there is a God then Morality is grounded in his consciousness. Without God, there is no consciousness in which to explain what Morality is or where it comes from. All we have is our own predilections and preferences without God. And who's to say yours are better than mine when we disagree? The fact that we will disagree on some points is a given.
Here is the bottom line: when I, as a Christian theist, argue that there exists a objective morality, based on God, I am not saying that God is limited or subjected to that standard. This is not saying that God can or does anything against that standard. God follows those standards because they are based on who God is. Anytime it seems like God has commanded anything that goes against that standard, one of two things is true: either we didn't understand the command or we don't understand the standard as well as we like to pretend we do. In addition, we need to keep in mind that the Bible is God's revelation of that standard. And looking into it there is more than enough about that standard that I would not have come up with on my own. And neither would you. I will discuss this more in an upcoming post about a study that suggests that when people think they are following God's commands, they are really only doing what they want to do.