The main thesis of this book is that abstraction, far from being confined to higher formsof cognition, language and logical reasoning, has actually been a major driving forcethroughout the evolution of creatures with brains. It is manifest in emotive as well as rationalthought. Wending its way through the various facets of abstraction, the book attemptsto clarify – and relate – the often confusing meanings of the word ‘abstract’ that one mayencounter even within the same discipline.