NATURALLY GOOD is a behavioral history of moral development traced through the writings of key 19th and 20th century thinkers beginning with Herbert Spencer and concluding with E. O. Wilson. The book is in response to an appeal by Charles Darwin for ethicists and biologists to take a close and careful look at the emergence of moral behavior within the human community based upon natural history rather than revelation of divine mandates. "As far as I know," said Darwin in 1871, "no one has approached moral development exclusively from the side of natural history." The book systematically explores the thoughts on moral development in the works of Spencer, Darwin, Marx, Freud, Sartre, Viktor Frankl, Albert Schweitzer, Abraham Joshua Heschel, Jean Piaget, Sir Julian Huxley, and E. O.Wilson.