Those who refuse to learn from history are condemned to repeat it
I do not know your religious bent but the Catholic faith has martyrs who refused to denounce their G*d in the face of death & torture. To speak for genocide is not that far from denouncing G*d in my mind.
The understanding to be obtained from the Inquisition or Hitler’s reign is that there are evil people in the world and that by contamination and in fear weak people will stand with the evil ones. The lesson is that one stands against evil wherever one finds it and cherishes & nourishes good because otherwise truly horrible things happen. Good men must join together to resist evil and learn to recognize it by it’s quest of power for the self and the disregard for the rights & value of the others that are being trampled.
Evil is a possibility in each of us; it is a part of being human. Embrace it for whatever purpose at your peril.