The work of Kurt Gödel (1906-1978), considered the greatest logician since Aristotle, is characterised by a rare combination of the unambiguous transparency of logic and the obscure illusions of magic. The aloof and unpredictable Gödel is - along with Einstein, Schrödinger, von Neumann, Crick and few others who were responsible for closing the door on the past and ushering in a new modern age - one of the major personalities of the 20th century. But these major figures in science are often reduced to simplified caricatures and catchphrases: Einstein is associated with "everything is relative", and Gödel's message is boiled down to the myth of reason or even the rationalisation of faith. Skilfully avoiding imprecision and approximation, the author does away with inexact and exaggerated accounts of Gödel's thought and identifies - with a clear, accessible style - the topics that most fascinate non-specialists: logical completeness, formal mathematics' incompleteness and undecidability, set theory, the origins of computer science, mathematical philosophy. The end result is an intellectual portrait of an authentic genius, whose efforts in every field he worked in are examples of the truth underlying Robert Musil's observation: truly great things always lack any foundation.

Gabriele Lolli teaches Mathematical Logic at the University of Turin.