Descartes, René ruled in Fatehpur Sikri Foreign visitors, including ambassadors from European countries, commented on the opulence of Akbar’s court and the beauty of Agra Akbar’s successor Jahangir (ruled 1605–27) held court at Agra, where he received Sir Thomas Roe, the ambassador of James I of England, but for most of his reign Jahangir resided in Lahore in modern-day Pakistan, or in Kabul in Afghanistan Only a few important buildings were added to Agra during Jahangir’s reign Jahangir’s son Shah Jahan was a great builder who greatly added to both Agra and Delhi His greatest legacy is the Taj Mahal, a great mausoleum he built for his wife, Mumtaz Mahal It is one of the wonders of the world Shah Jahan also built and improved many monuments in Delhi that include large city walls with grand gates, most notably the Ajmeri Gate, the Delhi Gate, the Kashmiri Gate, and the Turkman Gate Shah Jahan in 1648 began work on the Red Fort in Delhi to improve the city’s defenses In 1739, Nadir Shah, emperor of Persia, captured and looted Delhi, taking the fabulous jewel-encrusted Peacock Throne back with him to Persia In 1760, the Marathas attacked and looted Delhi again In 1761, the Jats captured Agra and sacked the city, including the Taj Mahal Nine years later it was captured by the Marathas, who held it until 1803, when both cities were taken by the British See also Mughal Empire Further reading: Asher, Catherine B Architecture of Mughal India Cambridge: Cambridge University Press, 1992; Havell, E B A Handbook to Agra and the Taj Calcutta: Thacker, Spink & Co., 1924; Richards, J F The Mughal Empire Cambridge: Cambridge University Press, 1993 Justin Corfield Descartes, René (1596–1650) mathematician and philosopher René Descartes was a metaphysician, mathematician, and natural philosopher responsible for changing the course of philosophy and creating analytic geometry and an influential physical theory His early life is obscure Born into a wealthy French family of physicians and civil servants, he was educated at the Jesuit College of La Flèche from 1606 to 1614, taking a law degree from the University of Poitiers in 1616 He then wandered through Europe as a soldier He later claimed that in 1619, in Germany, he had a vision of a new philoso- 103 phy Descartes envisioned himself as a new Aristotle, with a philosophy universal in its application In 1628, Descartes settled in the Dutch Republic, remaining there for 20 years Descartes was a loyal Catholic who, despite living in a Protestant society, never showed any interest in conversion He differed from Catholic orthodoxy in his acceptance of the Suncentered Copernican astronomy Although Descartes was in no physical danger from the church, he was shocked by his fellow Copernican Galileo Galilei’s condemnation in 1633 Abandoning a treatise on the verge of publication that would have systematically expounded his natural philosophy, Descartes turned to metaphysics to find a religiously unimpeachable basis for natural knowledge In 1638, he published Discourse on Method, setting forth his program for natural philosophy and three associated treatises he claimed exemplified his method on geometry, optics, and meteorology, including matter theory These works were in French rather than Latin, aimed at an educated public, rather than university scholars Descartes was the first notable European male intellectual to think of women as an important part of his audience The Discourse sets forth the famous cogito ergo sum (although not in those words), Descartes’s argument that the very process of thinking proves that the thinker exists This metaphysics was further elaborated in Meditations on First Philosophy, published with a number of objections from others and replies by Descartes in 1641 Descartes attempted to use the cogito as a foundation for both metaphysical claims (a logical proof of the existence of God) and physical ones—that which can be logically deduced from known truths can be certain Descartes’s proof of the existence of God is similar to the famous “ontological argument” of Anselm of Canterbury God’s perfection is so great that our “clear and distinct” idea of it could not have been caused by a being less perfect than God Indeed, the clearness with which we hold the idea of God is in itself proof of God’s existence Descartes was a rationalist who viewed logical consistency as prior to empirical observation As a natural philosopher, Descartes set forth a vision of nature as mechanical, a “mechanical philosophy.” He did so most systematically in his 1644 Latin textbook, Principles of Philosophy He claimed that the universe was full of matter, defined as that which occupied space—Descartes, like Aristotle, denied the possibility of a vacuum—and everything that occurred in the material universe could be explained by the