Jonathon Moses makes moral, political and economic arguments in favor of the free mobility of human beings across national borders. Pointing to the importance of immigration to the sucess of many nations, he shows that Europe itself now faces a falling population, and has over the past fifty years actively encouraged huge immigration from other countries. There is near consensus across the political spectrum that the free movement of goods and free movement of capital are good for economies, and therefore should apply to people as well.