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Des·cartes

(dā-kärt), René 1596-1650.

French mathematician, philosopher, and scientist who is considered the father of analytic geometry and the founder of modern rationalism. His main works, Meditations on First Philosophy (1641) and Principles of Philosophy (1644), include the famous dictum "I think, therefore I am."

(click for a larger image)

René Descartes

after a c. 1649 portrait by

Frans Hals (1580?-1666)

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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