If you keep removing single grains of sand from a heap, when is it no longer a heap? From discussions of the heap paradox in classical Greece, to modern formal approaches like fuzzy logic, Timothy Williamson traces the history of the problem of vagueness. He argues that standard logic and formal semantics apply even to vague languages and defends the controversial, realist view that vagueness is a form of ignorance - there really is a grain of sand whose removal turns a heap into a non-heap, but we can never know exactly which one it is.
'Nothing should henceforth be written on vagueness which fails to learn from this book. It should be read not only for its contribution to vagueness, but also for what it says about knowledge; for the purity of its style ... and as an example of philosophy at its very best.' - British Journal for the Philosophy of Science
'This is a marvellous book. Not for a long time have I read anything which was at the same time so easy and pleasant to read and so stimulating.' - Philosophical Books