I just read the recently published 'Moral Uncertainty' by Will MacAskill, Krister Bykvist, and Toby Ord. It's an excellent book with significant practical implications. As such, I originally intended to write a brief review — which ballooned into this monstrosity. In any case, I hope such a summary is useful for anyone curious about the book's main arguments, and the subject of moral uncertainty more generally. I would also be very grateful for feedback on this — anonymous is fine.