No philosophical idea, no matter how small, can live alone. Ideas always gain their force, power, and life from their surroundings - their ecosystem. The ecosystem of ideas defended in this book comes from the ancient Greek philosopher Aristotle and his medieval interpreter, Thomas Aquinas. The ongoing relevance of their philosophical thought to twenty-first century issues is opened up in fascinating ways in this book. Life, the Universe, and Everything is the product of thirty years of teaching introductory courses in philosophy. Assuming no prior background, it only requires of readers an enquiring mind and a willingness to think carefully. An ideal guide to the big questions we face.