Abstract
This is the first and complete Japanese translation, with an introduction and notes, of the 6 Latin letters exchanged between Descartes and Beeckman in 1619. They show us quite vividly the intellectual activities of young Descartes at Breda in Holland. It is true that the Dutchman taught Descartes to use mathematics in the study of physics,but a Cartesian project of science was wider and more universal than that of Beeckman. This difference seems to be one of the main causes of a conflict between them in the future.
