CONTENTS xiii 49.The Emergence of Abstract Algebra,1136 1.The Nineteenth-Century Background,1136 2.Abstract Group Theory,1137 3. The Abstract Theory of Fields,1146 4.Rings,1150 5.Non-Associative Algebras, 1153 6.The Range of Abstract Algebra,1156 50.The Beginnings of Topology,1158 1.The Nature of Topology,1158 2.Point Set Topology,1159 3.The Beginnings of Combinational Topology,1163 4.The Combinational Work of Poincare,1170 5.Combinatorial Invariants,1176 6 Fixed Point Theorems,1177 7.Generalizations and Extensions,1179 51.The Foundations of Mathematics,1182 setThe Re tMche Th ch istic School, 1192 6.The Intuitionist School,1197 malist School,1203 8.Some Recent Developments,1208 List of Abbrevations Index