  According to Albert C. Knudson, personalism is “the ripe fruit of more than two millenniums of intellectual toil, the apex of a pyramid whose base was laid by Plato and Aristotle.” Catholic personalists emphasize more specifically the decisive role of medieval thought, and in particular scholasticism, for the development of personalism. Étienne Gilson, for instance, has observed that where Plato locates the center of reality in ideas with concrete instantiations of these being merely accidental, and Aristotle places emphasis not on numerical individuals but on the universal specific form, Thomas Aquinas saw the individual person as unique among beings because of reason and self-mastery. Though none goes so far as to call Aquinas a personalist, some suggest that he furnished the necessary soil in which personalistic theory could take root. In this regard, Karol Wojtyła wrote that Aquinas “provided at least a point of departure for personalism in general.”