(1) _As Child and Student_ (1596–1613). At home until he was eight years old (1596– 1604). At the Jesuit school at La Flèche until he was seventeen (1604–1613). (2) _As Traveler_ (1613–1628). Descartes studies “the book of the world.” At Paris (1613–1617), in retirement and study. In Holland (1617–1619), nominally attached to the army of Maurice. First Journey (1619–1621), going through Bavaria, Austria, north to the shores of the Baltic and back to Holland. The greater part of these two years were spent in Bohemia, enrolled in the army of the Emperor. He was on this journey when his mental crisis occurred,――at Neuberg, in Austria, in 1619. It was then that he discovered either analytical geometry or the fundamental principle of his philosophy. In Paris again, 1623. Second Journey (1623–1625), to Switzerland and Italy, making a pilgrimage to the shrine of Loretto. (3) _As Writer_ (1629–1650). In Holland (1629–1649). For the sake of absolute seclusion from inquisitive visitors, Descartes changed his residence in Holland twenty-four times and lived in thirteen places. All his correspondence passed through Mersenne. During these twenty years he made three journeys to France. Thus this period of absolute retirement became his period of literary production, chiefly between the years 1635 and 1644. He wrote his _Method_ (1635–1637). _Meditations_ (1629–1641). _Le Monde_ (1630–1632), published posthumously. _Principles_ (1641–1644). _Passions_ (1646–1649). (4) _In Stockholm, Sweden_ (1649–1650). The romantic side of the life of Descartes appears in his book on the _Passions_, which he wrote for the Princess Elizabeth, and also in his acceptance of the invitation of the Queen of Sweden to reside at her court and become her tutor. He died there from the rigors of the climate after a residence of one year.