In 1942 G.E. Moore first wrote about the curious sort of 'nonsense' exhibited by the statement 'it is raining but I do not believe it'. What Moore discovered was a species of blindspots: consistent propositions that cannot be rationally accepted by certain individuals even though they might be true. In this book, Professor Sorenson aims to provide a unified solution to a large family of philosophical puzzles and paradoxes through a study of blindspots . He devotes special attention to revealing their role in 'slippery slope' reasoning.