Regarding artists and their relation to goodness, it occurred to me that a better correlation might be:
Those who explore human action/moral matters should have some notion of the good.
Those who produce artefacts should have some notion of the beautiful.
A writer is an artist and, when treating of human actions (as opposed to documenting history/etc.), is dealing with characters who either believe that what they do is good/evil or with a character who rejects the notion of good itself and uses some other valuation system for determining action.
But if the author himself is ambivalent, it may do him a disservice when trying to capture a moral dilemma and full range of human responses/emotions. Which isn't to say that the author denies the phenomena of a dilemma (emotions, thought-processes, etc.), but he might not appreciate the soul-gripping-depths of those straddling heaven and hell.
I'm not sure if I'd assert that the atheist-turned-religious (or vice-versa) would be *best* able to put into words the whole-spectrum of characters in world-with and world-without God (which seems entailed from the above).
Maybe it's only that those with experience write about things in a way that resonates more with others who have had the same experience and perhaps authors might have enough imagination/sympathy to surmount the difficulty. Men write about women, women about men, saints about sinners, sinners about saints. By necessity, writers treat of characters who do and say things the author would never do or say, or hold positions the author himself would never dream of espousing. But being-woman or being-close-to-God yields a writing with familiarity, I'd imagine.
So perhaps it's sufficient to say that the author with experience of good and evil (which every human has) and a notion that these forces (though I hate to call evil a force -- evil is lacking and impotent) operate in human lives. And leading a life of virtue, having an eye to the good, might make one more sensitive to that, to those little reverberations of the soul, to its architectonic yearning for something beyond and greater. If you have an eye to the evil, eventually even good becomes tainted and all motives turn into ulterior and selfish ones - even the man who desires beatitude would be scoffed at as having the ultimate selfish desire.
BUT this only serves to make me more confused in my mind. Clearly, I am not precisely qualified to construct a bridge between morality and art though I'm sure it's there and want to read more on it.
As to dancers and painters, I likewise think a correlation exists between a notion of the beautiful and their ars (and in my sleep-lacking state I'm imagine two people yelling at each other 'IT'S EITHER YOUR ARS OR MINE!'). not quite sure, yet, about this correlation, since a brief dip into notions of beauty reveals a split between transcendental, metaphysical, and aesthetic beauty and their relation to works of art. So, at most, for now, I'll hazard only that *some* notion of beauty is beneficial for an these artists to have. And that beauty does not equate with pretty.
[If there are any recommendations for a direction to pursue in this respect, I'm all eyes.]