On Wednesday, October 16, Prof. Ernest Sosa delivered the annual Stevens Lectureship in the Humanities. The Stevens Lectureship is an annual lecture that covers issues in history, English and philosophy. Sosa is the Romeo Elton Professor of Natural Theology and professor of philosophy at Brown University. He is also an editor for two prestigious philosophical journals, and he has lectured on every continent save Antarctica. Sosa’s lecture “Philosophical Skepticism: It’s Historical Roots and Contemporary Relevance” described some of the ramifications of doubt in philosophy and some of the thinkers that have pondered such problems. Sosa opened his lecture by saying that “knowledge is a matter of degree in many respects.” The factual veracity of many points is by no means a certainty. To make his point, Sosa held out his hand and asked how could one be sure that the hand was actually there. Of course, we can see the hand, but our reasons for saying that the hand exists rest on a number of assumptions, i.e. our sense of sight, proportion, etc. Question the assumptions, and the evidence for the existence of the hand is thrown into doubt. Of course, excessive skepticism can lead to fallacies and unnecessary uncertainty. “The coherence of our minds goes with a love of understanding,” said Sosa. Relational properties, ways of seeing how things fit into wider wholes, and other principles are important in deciding the veracity of events. Questions are necessary in order to attain knowledge. Sosa declared that all questions posed can be answered in one of three ways, “yes, no, or maybe.” If the answer is “no” or “maybe,” then the evidence to support a point is inconclusive. Philosophy can be a tricky business. Sosa then continued by discussing the conclusions of many famous philosophers. He mentioned Bonjour’s Generalization, which leads to the conclusion that “if you start requiring too much, you go down a skeptical, never-ending road.” Doubt has its place in philosophy, but too much can be carcinogenic. The musings of Descartes were also brought up. Descartes believed that theology was important if one was to study mathematics properly. “Only once you do theology and are placed in the universe can you get somewhere with your faculties,” quoted Sosa. Sosa didn’t quite agree with Descartes’ conclusions, but he did agree that sound conclusions need some grounding point. Skepticism has an important role in philosophy, but when pushed too far doubt can render philosophy meaningless.