Human Sensation in Galileo and Aquinas: Is Cognition Strictly Material?

With Fr Brian Chrzastek, OP, MDiv/STB, STL, LPhil, PhD, Assistant Professor of Philosophy, Pontifical Faculty of the Immaculate Conception, Washington, DC.

In the chapter devoted to “Copuscularianism,’ in his Assayer, Galileo describes human sensibility in terms of the four physical elements of the Aristotelian tradition. This bears a striking resemblance to Aquinas’ discussion of the same considerations in his Summa Theologiae (Ia., 78, 3). Perhaps the main difference is that where Galileo, foreshadowing a trend that is evident in Locke and others, is intent on reducing sensibility to purely material terms. St. Thomas, by contrast, while granting the material aspect of human cognition, is intent to articulate its spiritual nature. This lecture will explore the philosophical breath of Aquinas’ approach as a critique of Galileo’s alternative.