Book excerpt: Plato's Timaeus contains a powerful and influential myth, of the construction of the universe by a divine craftsman. A god imposes reason on necessity, to bring order from a primeval 'receptacle' of disordered matter. There results the 'child' that is the cosmos - a copy of an eternally-existing perfect model. Here eight new essays from a distinguished international cast, explore aspects of this challenging work: the principles of the mythical narrative, how the world soul and human body are formed, implications for illness - mental and physical, the importance of music and harmonious proportion. Later developments are also treated: Aristotle's theory of generation, the commentary of Proclus and elements of modern evolutionary theory.