Tomorrow is MLK day. In a nice coincidence, I was just reading this excerpt from a letter to his future wife from 1952.
"I imagine you already know that I am much more socialistic in my economic theory than capitalistic. And yet I am not so opposed to capitalism that I have failed to see its relative merits. It started out with a noble and high motive, to block the trade monopolies of nobles, but like most human systems it falls victim to the very thing it was revolting against. So today capitalism has outlived its usefulness. It has brought about a system that takes necessities from the masses to give luxuries to the classes." ~ Martin Luther King.
I think Dr. King is pretty obviously a man who appeals to arguments founded on moral truths, both couched in religion and in humanism. A lot of socialists I know of are passionate and idealistic, perhaps to a fault. It's weird to me to think of socialism as any more amoral than any other socioeconomic ideology.