In the same vein as GP, the validity of an idea is independent of whether the people who held them owned slaves. If you don't own slaves but think the sun rises

In the same vein as GP, the validity of an idea is independent of whether the people who held them owned slaves. If you don't own slaves but think the sun rises from the west, you're still wrong. Besides, if the only things to be learned from history are those from whom you deem morally clean, I'd wager there's precious little left at all.