Funny you should ask this: The philosopher Tim Mulgan just published a nice article exploring this question, particularly its ethical and meta-ethical implications. Here's Mulgan's piece: https://aeon.co/essays/how-the-discovery-of-extraterrestrial-life-would-change-morality

Not sure what to say about trivialism -- but one thing you've put your finger on is that because philosophers tend to question the assumptions of ordinary thought, they will often defend claims that are surprising, controversial, or counterintuitive. The examples you mention (rape, incest, etc.) are ethical conclusions. But philosophers have defended a wide array of unconventional or surprising claims about knowledge (skepticism), metaphysics (we don't exist), and so on. In ethics, it's not that rare for philosophers to defend unpopular claims. I'm not aware of any philosophers who defend rape, the torture of infants, or serial murder. But certainly some have asked not-silly questions about the taboo subjects you mention. - On incest, many philosophers have wondered whether the practice is really harmful, violates norms of consent when it occurs between mature adults, etc. - Regarding terrorism, many philosophers have questioned whether there is so clear an ethical line between terrorism and other forms...

First, philosophy can contribute to world peace by helping us think through the ethical importance of peace -- and of war. Philosophy has a long tradition of inquiry into the conditions for morally justifiable violence. A few philosophers have glorified war. Others have argued that war is justified when war advances a state's interests' ('realists') or when certain conditions are met (just war theory). Other philosophers have advocated for pacifism. Good overviews of these positions are available here: http://plato.stanford.edu/entries/war/ http://plato.stanford.edu/entries/pacifism/ Second, philosophy can contribute to world peace by undermining the conditions under which war tends to thrive and by pointing to alternative ways to resolve conflicts that might otherwise lead to violence. Starry-eyed though this might sound, philosophical inquiry tends to induce, on the one hand, modesty or humility about one's own beliefs, as well, on the other hand, as a greater appreciation for the merits of others'...

A tough one - I'd be interested to see other panelists weigh in! The first thing to say is that it's hard to identify any limits to the subject matter of philosophical questions. Traditionally, philosophy has addressed questions about human nature, the nature of reality, knowledge, value, beauty, reason, and so on. But in recent decades, philosophers have turned their attention to an ever-widening circle of topics: medicine, law, the family, race, sports, business, gender, technology, religion the environment, and so on. So it doesn't seem as if the defining characteristic of a philosophical question is what it asks about . One characteristic of a philosophical question is that it tends to be general. This is not to deny that we are often motivated to ask philosophical questions by very specific concerns. We might be motivated to ask the philosophical question 'what makes a person morally responsible for our actions?' by our interest in whether Charles Manson was responsible for his criminal actions....