Are ambition and altruism compatible? How ambitious should we be if we want to do as much good in the world as possible? How should we handle expected values when the probabilities become very small and/or the values of the outcomes become very large? What's a reasonable probability of success for most entrepreneurs to aim for? Are there non-consequentialist justifications for longtermism?Habiba Islam is an advisor at 80,000 Hours where she talks to people one-on-one, helping them to pursue high impact careers. She previously served as the Senior Administrator for the Future of Humanity Institute and the Global Priorities Institute at Oxford. Before that she qualified as a barrister and worked in management consulting at PwC specialising in operations for public and third sector clients. Follow her on Twitter at @FreshMangoLassi or learn more about her work at 80,000 Hours at 80000hours.org.