第23页 Chapter 1: I Am Therefore I Think

"One of the characteristics that sets man apart from all the other animals (and animal he indubitably is) is a need for knowledge for its own sake."
(Vincent Dethier, 1962, pp. 118-119)
On the most basic level ,we must think to remain alive. To think is the most essential human characteristic. Over three centuries ago, the French mathematician and philosopher René Descartes, after one of the most thorough and skeptical purges in intellectual history, concluded that he knew one thing for certain:"Cogito ergo sum—I think therefore I am." But to be human is to think. Toreverse Descartes,"Sum ergo cogito—I am therefore I think"