Following Karel's logic, since he wasn't around for whatever his ancestors may or may not have done to someone elses ancestors he isn't to be held responsible for any of it. Ok then, If you can't be responsible for the bad, then you also ought not benefit from any possible gain that his ancestors may or may not have had from said behavior. That's the logic of his argument. I'm willing to go there so long as he's willing to give up any and all advantages he may have received on the part of his ancestors AND does not pass on any such fortunes (monetary or other) to his children. Otherwise the argument falls on it's face in practice.