Theists: What do you mean when you say that God is 'perfect'?

[Angrboda]

I hope you're not defaulting to the supposition that God is "all things to all men" -- that God embodies all perfections that could possibly be.  

That is two contradictory concepts in one sentence. The notion that God is “all things to all men” is the exact opposite of the notion that God embodies all perfections.
The first allows someone to posit things like ‘perfectly evil’ or ‘completely ugly’. Personally, I have no idea what kind of theory of value would allow someone to contrast perfect good with perfect evil without contradiction. Perhaps you have something in mind.

In the Scholastic tradition, evil is considered a deficiency, a “lack of the good that ought to be there,” to paraphrase Augustine. A basketball is definitely more of a perfect sphere than say a loosely packed snowball. The pieces of a tangram puzzle are more perfect triangles than either a yield sign or a spanakopita.

Similarly, human morality consists of more perfectly manifesting the virtues of humanity. An insane person lacks the rationality that is natural to being human. A sociopath lacks the empathy that is natural to a human. A thief lacks conscience, etc. The difficulty of flushing our virtue ethics is determining what exactly the natural and normative virtues of humanity are. That doesn’t bother me too much. The debate about what those virtues are only makes sense after mutual agreement that there actually are such virtues.

You didn't actually answer the question, so I'm forced to read between the lines. Either you do consider God to embrace only desirable perfections (as seems implicit from the definition of perfect), or that God personifies both desirable and undesirable attributes. I don't agree with the notion that evil is the privation of good, but that is irrelevant as that is just a species of a class of objectors. Either God's attributes consist of all possible attributes, including the undesirable, or they do not. So long as God is biased towards the maximal of certain things, not others, my objections hold.

If a theist is to justify why God is all loving, and that itself is supposed to be a desirable thing to be, the only place we can turn for that bias is to God himself.  But then God's perfections become simply those things which God himself considers to be desirable to be perfect in.  We end up with a curious construction in which God's supposed greatness rests upon what he himself considers great.

That’s like someone saying that the standard for a perfect sphere is whatever he considers it to be like. If he thinks popcorn balls are the standard by which all spheres should be judged, that leads to the bizarre conclusion that popcorn balls make better spheres than a glass marbles. God is not a post-modernist.

Your objection only makes sense if there does exist a standard external to his by which one judges said glass marbles to be more perfect. Since, I assume, that you are not suggesting that God is perfect only insofar as he adheres to an external standard of goodness or sphericity, the situation you describe is not at all analogous to the one described. You've made a false and irrelevant analogy. What point you meant to make by claiming that God is not a post-modernist is only something that I expect you can unpack more fully, rather than simply being an example of a rather shoddy attempt at appeal to ridicule.

It isn't so much that you decry the lack of a foundation in alternate moral theories.  They have their own suppositions about the ultimate good -- nature, our species, society, well-being, the planet -- you simply disagree on what the highest good actually is, and whether there is any foundation for considering the specific highest good to be rationally justified.  If I'm at all familiar with your arguments, it is that you believe these 'highest goods' are not ultimately justified, whereas God as the highest good supposedly is justified.  For the reasons stated above and others, I think that your highest good is no better justified than any of the alternatives.  You simply believe it is.  And when I asked for your reasons in the Euthyphro response, I believe you said, "[It] just is."  How you think that any less arbitrary than any of these other highest goods is a mystery to me.  It only becomes worse when I observe that the existence of your highest good is based essentially upon bare assertions made by mortal men scattered throughout the dark recesses of history.

As I feared, we appear to be talking past one another yet again. Values based only on contingent things do not satisfy the criteria for a highest good, i.e. that of resting on absolutes, and as such any source of value other than one tracing back to an absolute is arbitrary. This has been the reasoned opinion of thoughtful mortal men since the dark recesses of history and on through modern thinkers like Nietzsche and Sartre. It is a contemporary conceit that people who lived in by-gone eras are any less wise or rational than today.

In line with Munchausen's trilemma, things can fail to be meaningful both if they fail to terminate in a meaningful foundation, and if they depend upon their meaning of being defined in terms of themselves. A circular definition is as vacuous as one that has no ultimate meaning. Despite your attempt to counter my observation that God's values are circularly defined (above), you have so far failed to do so. I don't think you ultimately can defuse the vacuity charge as applied to your God's values. Which would leave us with a situation in which, even given the most generous assumptions possible, one still cannot find such a classically defined highest good even in the purely abstract concept of a non-contingent God. I think in that case, it makes perfect sense to question traditional reasoning about such things.