gh his senses but rests his whole system on the one truth that he cannot doubt, namely, the reality of his own mind and the radical difference between the mental and the physical aspects of the world(René Descartes: Discourse on Method (1637) http://www.wsu.edu:8080/~wldciv/world_civ_reader/world_civ_reader_2/descartes.html)."
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