In the framework of the 20th International Congress of History of Science (Liege 1997), a symposium was devoted to the historical work of Adolph P. Youschkevitch (1906-1993). The present volume includes the papers read during the symposium as well as contributions on current issues in the history of mathematics: mathematics as a cultural strength, mathematics from antiquity to the classical period, probability theory and its applications, mathematics in the 19th and 20th centuries.