What Is Thinking? What is Turing's Test? What is Gödel's Undecidability Theorem? How is Berners-Lee's Semantic Web logic going to overcome paradoxes and complexity to produce machine processing on the Web? Thinking on the Web draws from the contributions of Tim Berners-Lee (What is solvable on the Web?), Kurt Gödel (What is decidable?), and Alan Turing (What is machine intelligence?) to evaluate how much "intelligence" can be projected onto the Web. The authors offer both abstract and practical perspectives to delineate the opportunities and challenges of a "smarter" Web through a threaded series of vignettes and a thorough review of Semantic Web development.