Let us imagine that somewhere in present day South America a nation exists as the United States was constituted in 1789. George Washington is its president and Thomas Jefferson its secretary of state. It is a nation that allows only white males to vote, and its president, cabinet officials, and many of its citizens own slaves. If the America of 1789 existed right now, what would we think of it? Would it be right to invade it in order to liberate its people? Would we consider a complete embargo of it? Or would we recognize and cooperate with it, declaring its president and secretary of state political geniuses? Maybe we would do nothing and trust that in 100 years or so it will straighten itself out? - -Three hundred years ago, if a woman was raped and became pregnant we'd kill the rapist and spare the baby. Today, we spare the rapist and kill the baby. -- One hundred years ago only heterosexual marriages were legal. Today, political leaders from around the world are celebrating gay relationships. How and why does our moral outlook change in such matters? -- By the time you are done reading this book, you will have concrete answers to these questions and many more.