WHAT WOULD YOU ABSOLUTELY NOT SELL?

I have another blog where I express my views on life at http://saywhatiought.blogspot.com/
I have been thinking lately how ethics fits in with an Ebay business. Is there anything that you would absolutely would not sell to another person no matter what the price. Are there things that are better thrown away. Today I had a chance to get a lot of free books on religious philosophies that I strongly disagree with. They were actually valuable books. I passed on them. In the past I have sold books that I disagree with but these were stronger than usual. I do include a pamphlet on God , Jesus , the Christian faith with every item I sell. When I sold a copy of the Egyptian book of the dead the buyer was presented with a tract as well. Does this justify selling a bad book? Feel free to comment......