To argue the other side, I think it is wrong because you can't know that the good you do will outweigh the harm you do. But everything, even seemingly beneficia

To argue the other side, I think it is wrong because you can't know that the good you do will outweigh the harm you do. But everything, even seemingly beneficial things, have both good and bad effects and morality seems to be the art of balancing them. However, if somehow you had knowledge that the long-term good far outweighed the short-term harm, it seems like it becomes the ethical thing to do. In real-life you don't usually get that kind of certainty though.