I ' m still kind of confused , but I think I understand what you mean . Science can ' t let us derive an ought from an is . I do not disagree . However , if I say human suffering is bad , and human happiness is good , then given these subjective definitions of good and bad we can fairly easily see how science could be useful for questions of morality . So for instance in your trolley example . If we ' re trying to judge based on net positivity or negativity it ' d be trivially easy to use science to determine the moral choice , given these subjective definitions . Now we can then get into debating over if we have enough data to make conclusions , or these subjective definitions , etc , but that doesn ' t mean these questions can ' t be asked , just that it may be impossible to figure out . Just because we can ' t reasonable answer question doesn ' t mean the question is nonsensical or lacks answer . If I asked you how many birds are currently in flight above Earth , there ' s no way you could answer , but an answer absolutely exists . Sorry I kind of rambled a bit .