In this philosophical self-help, author and academic King (Peace at Any Price, How the World Failed Kosovo) reveals a logical method for making ethical decisions that he calls a ""Newtonian revolution"" in moral science (aka the ""DNA of right and wrong""), combining the golden rule and Jeremy Betham's calculus for determining ""the Greatest Happiness for the Greatest Number"": ""Help someone if your help is worth more to them than it is to you."" Most of the book is devoted to elaborating this principle, offering an intro-to-philosophy overview and clear arguments illustrated with numerous thought-experiments. (Should a man of integrity agree to work in a dictator's torture chamber in order to replace the evil sadist currently manning the switch? Yes.) Everyday ethical considerations abound; King is even able to formulate ""a credible rule that tells us when to lie."" Although his system is most easily applied to one-on-one situations and small groups, it tends to break down in large groups; King concludes that, just as Newton's revolution was superseded by quantum mechanics, his principles are inherently limited by real-world complexity. Still, an academic audience interested in practical philosophy will find King's approach to everyday morals bracing, optimistic and perhaps inspiring.