Descartes later did a volte-face by jettisoning his Cogito ergo sum entirely, and now accepting what his senses tell him! He did this by using entirely separate arguments, not deduced from the Cogito at all, to prove that God did after all exist! And that He was not a Great Deceiver who would deceive Descartes about what came to him via his senses. So Descartes could now accept what his senses…