>Well, this is a thread about free will, right. In the first place it is impossible to think about morality without the concept of free will. We can't be said to have made a "choice" about anything if we don't possess self-awareness and higher mental functions like rational reasoning.
>So thus far morality is contingent on the mind.
The problem with your argument here, user, is it requires understanding morality from a subjective, mind-dependent way from the outset. Think of it this way, if I said, "It's impossible to think about mathematics without free will, self-awareness, and higher mental functions like rational reasoning." You'd call me silly and rightly point out "No, mathematical facts would still exist, those hypothetical beings just wouldn't' haven't access to it."
>Further, the ability to assign value to objects is integral for moral functioning.
>In order to make a choice we need to assign value to different options.
Again, if moral facts were mind-independent, then it wouldn't require people to 'assign value' because the value and moral properties already exist.
>(a)different people can assign different values to the same object.
So what? People disagreeing over math and science doesn't automatically conclude both math and science are subjective, it could also mean some people are wrong.
>(b)the mechanism and extent of this is dependent on the biological/physical functioning of our brain.
You're committing the same error you did before. Moral realism includes a distinction between "what we do believe" and "what we ought to believe," and is primarily concerned with the latter. The point I'm making here is, just like with the mathematical facts example, our moral beliefs being continent on our biological/physical make-up doesn't have anything to do with whether those beliefs are correct or if true facts exist elsewhere. In short, a dog's inability to understand and incorporate mathematical facts has no relation to whether those facts are real.
I'll reply once I come back from smoking a cig.