Tell me why -- An idea is born -- Universal acid -- The tree of life -- The possible and the actual -- Threads of actuality in design space -- Priming Darwin's pump -- Biology is engineering -- Searching for quality -- Bully for brontosaurus -- Controversies contained -- The cranes of culture -- Losing our minds to Darwin -- The evolution of meanings -- The emperor's new mind, and other fables -- On the origin of morality -- Redesigning morality -- The future of an idea.