From the reviews: "The book under review is a collection of twenty-one survey or expository lectures given by its distinguished author during the period 1943 and 2004 ... . All are (broadly) in the fields of topology, algebra and differential geometry. ... Students will learn an important and substantial swathe of 20th century geometrical mathematics by carefully reading this delightful book." (Ross Geoghegan, Mathematical Reviews, Issue 2008 c) "The papers are arranged chronologically, and cover more than 60 years of work. ... The collection is rounded out by a couple essays on the place of mathematics in culture and its future. ... I heartily recommend adding it to your library." (John McCleary, MAA Online, February, 2009)

• L’idée de dimension.- Topologie und Algebra.- Complex-analytic manifolds.- Homotopie et dualité.- Groupes d’homotopie et dualité.- Homotopy and cohomology theory.- Simple homotopy type and categories of fractions.- Some recent developments in the homology theory of groups.- Poincaré duality groups of dimension two are surface groups.- Continuous solutions of linear equations — An old problem, its history, and its solution.- Mathematics: Questions and Answers.- Hurwitz-Radon matrices revisited: From effective solution of the Hurwitz matrix equations to Bott periodicity.- Birth of fibre spaces, and homotopy.- 4-Manifolds, group invariants, and ? 2-Betti numbers.- The Euler characteristic — a few highlights in its long history.- Topology, algebra, analysis — relations and missing links.- to ?2-methods in topology: Reduced ?2-homology, harmonic chains, ?2-Betti numbers.- Die Zukunft der Mathematik Ein Rückblick auf Hilberts programmatischen Vortrag vor 100 Jahren.- Kolmogorov and contemporary mathematics.- Is algebraic topology a respectable field?.- Social choice and topology. A case of pure and applied mathematics.

From the reviews: "The book under review is a collection of twenty-one survey or expository lectures given by its distinguished author during the period 1943 and 2004 ... . All are (broadly) in the fields of topology, algebra and differential geometry. ... Students will learn an important and substantial swathe of 20th century geometrical mathematics by carefully reading this delightful book." (Ross Geoghegan, Mathematical Reviews, Issue 2008 c) "The papers are arranged chronologically, and cover more than 60 years of work. ... The collection is rounded out by a couple essays on the place of mathematics in culture and its future. ... I heartily recommend adding it to your library." (John McCleary, MAA Online, February, 2009)

• L’idée de dimension.- Topologie und Algebra.- Complex-analytic manifolds.- Homotopie et dualité.- Groupes d’homotopie et dualité.- Homotopy and cohomology theory.- Simple homotopy type and categories of fractions.- Some recent developments in the homology theory of groups.- Poincaré duality groups of dimension two are surface groups.- Continuous solutions of linear equations — An old problem, its history, and its solution.- Mathematics: Questions and Answers.- Hurwitz-Radon matrices revisited: From effective solution of the Hurwitz matrix equations to Bott periodicity.- Birth of fibre spaces, and homotopy.- 4-Manifolds, group invariants, and ? 2-Betti numbers.- The Euler characteristic — a few highlights in its long history.- Topology, algebra, analysis — relations and missing links.- to ?2-methods in topology: Reduced ?2-homology, harmonic chains, ?2-Betti numbers.- Die Zukunft der Mathematik Ein Rückblick auf Hilberts programmatischen Vortrag vor 100 Jahren.- Kolmogorov and contemporary mathematics.- Is algebraic topology a respectable field?.- Social choice and topology. A case of pure and applied mathematics.