After reading this book and then reading other comments on this book, I felt compelled to put in my two cents worth. Contrary to another reviewer's opinion, this book is NOTHING like the Feynman lectures. Those books are so well written they can be read and understood by people with no background in physics. This text is complex and elegant in some places, but not something I would really recommend for a beginner (ie. someone unfamiliar with abstract models of computation). If you want a book that conveys the same material in a much more concise and understandable manner, buy the Sipser text.