  Descartes was not the first philosopher to formulate an ontological argument. An earlier version of the argument had been vigorously defended by St. Anselm in the eleventh century, and then criticized by a monk named Gaunilo (Anselm’s contemporary) and later by St. Thomas Aquinas. Aquinas’ critique was regarded as so devastating that the ontological argument died out for several centuries. It thus came as a surprise to Descartes’ contemporaries that he should attempt to resurrect it. Although he claims not to be familiar with Anselm’s version of the proof, Descartes appears to craft his own argument so as to block traditional objections.