The Euthyphro Dilemma

I often hear theists give arguments for the existence of God, but rarely hear arguments to the contrary. Indeed many atheists tend to have a consensus that it isn't possible to disprove a deity's existence, so atheists focus on positive arguments given by theists. There is one argument that, while not proving God's nonexistence, does lead the theist to an unwanted conclusion: the Euthyphro Dilemma.

Atheists often groan when we hear a Christian insist that the Bible is the unequivocal place we get our morality. Invariably the reply is that one would have to slaughter homosexuals (Leviticus 20:13), could own slaves (Leviticus 25:44), and stone women who are not virgins on their wedding night (Deuteronomy 22:13-21), if one believed that. The atheist then adds that any sane person with a decent moral compass would obviously not do such things, so he or she must get his or her morality from elsewhere or that person could not cherry pick around those horrid rules.

But what if we get rid of the horrid and immoral God of the Bible in favor of a more amorphous and ambiguous Deistic god? Can we do better by saying a nebulous creator of the universe grounds our morality as absolute? It seems reasonable that such a god would. The Euthyphro Dilemma tries to say no by showing that God either gets his morality from some other objective source or makes it up (which is arbitrary). In neither case, as the argument goes, is God the source of absolute morality. Here is the argument:

Is something good because God commands it (1), or does God command it because it is good (2)? If (1) then God could command anything he wishes since he is the source of morality, so morality is arbitrary. If (2) then God isn't the source of morality, so we don't need Him. Therefore in either case God is not the source of absolute morality.

After some arguments and attempts to show the dichotomy is a false one, Deists invariably converge to the following answer to show the argument to be wrong: God does not possess good, but is the paradigm of Goodness; he is the very definition of good by his nature.

This is where the one posing the dilemma replies: then we shall express the Euthyphro Dilemma in a reworded form. Do you define God as "the Good"/the paradigm of Goodness from a priori moral knowledge external to God and saw that He coincided with it (1), or did you define God as the paradigm of Goodness without external knowledge (2)? If (1) then you didn't need God to determine morality, or if (2) you defined God as moral arbitrarily, and could have chosen Gandhi or Hitler, for example.

I think this last statement of Euthyphro's Dilemma is irrefutable. One either has to have a priori knowledge of what is good to recognize something else as good (God), or one must accept something as a standard arbitrarily. If one chooses the second option then God could barbecue babies and one would have to say it is a moral act since we defined him to be moral.