“Cogito, ergo sum,” or “I think, therefore I am.” René Descartes initially published this philosophy in French in 1637 as “je pense, donc je suis,” but the Latin became more widely known when it appeared in his “Principles of Philosophy,” published in 1944. “Cogito, ergo sum” remains one of the fundamental tenets of Western philosophy. “Cogitate” may not be the standard word choice when looking for a synonym of “to think,” but it will show off some philosophical chops and brain power.