Vol. 21 Num. 1 (2001) Pierre Berdot , Claudine Blanchard-Laville , Alain Bronner Mathematical knowledge and its relation to the knowledge of mathematics teachers: linked traumas and resonances of identity2 Ian Stevenson Disruption and disclosure: learning to model spherical geometry12 Brent Davis Why teach mathematics to all students?17 Nathalie Sinclair The aesthetic is relevant25 Celia Hoyles Steering between skills and creativity: a role for the computer?33 Arthur B. Powell , Marilyn Frankenstein In memoriam Dirk Jan Struik: Marxist mathematician, historian and educator40 Dave Hewitt Arbitrary and necessary: part 2 assisting memory44