  During 1917–24, Weyl directed his energies equally to the  development of the mathematical and philosophical foundations of  relativity theory, and to the broader foundations of mathematics. It  is in these two areas that his philosophical erudition, nourished  from his youth, manifests itself most clearly. The year 1918, the  same year in which Space-Time-Matter appeared, also saw the  publication of Das Kontinuum (The Continuum), a  work in which Weyl constructs a new foundation for mathematical  analysis free of what he had come to see as fatal flaws in the  set-theoretic formulation of Cantor and Dedekind. Soon afterwards  Weyl embraced Brouwer’s mathematical intuitionism; in the early 1920s he published a number of papers elaborating on and defending the  intuitionistic standpoint in the foundations of mathematics.