Agnès Arnauld (1593—1671) An abbess of the Jansenist convent of Port-Royal, Mère Agnès Arnauld developed an Augustinian philosophy shaped by the mystical currents of the French Counter-Reformation. Her philosophy of God depicts a deity who is radically other than his creatures. Only a negative theology, a theology of what God is not, can explore the divine attributes. In her ethical theory, Mère Agnès contextualizes moral

Frege’s Problem: Referential Opacity The problem of referential opacity is to explain why a certain inference rule of classical logic sometimes produces invalid-seeming inferences when applied to ascriptions of mental states. The rule concerns substitution of terms for the same object, and here is one of the controversial examples. It involves the mental states of Lois Lane, who believes that Superman can fly. However, she

Jean-François Lyotard (1924—1998) French post-structuralist philosopher, best known for his highly influential formulation of postmodernism in The Postmodern Condition. Despite its popularity, however, this book is in fact one of his more minor works. Lyotard’s writings cover a large range of topics in philosophy, politics, and aesthetics, and experiment with a wide variety of styles. His works can be roughly divided into three categories: early

Immanuel Kant: Logic For Immanuel Kant (1724–1804), formal logic is one of three paradigms for the methodology of science, along with mathematics and modern-age physics. Formal logic owes this role to its stability and relatively finished state, which Kant claims it has possessed since Aristotle. Kant’s key contribution lies in his focus on the formal and systematic character of logic as a “strongly proven” (apodictic) doctrine.

Mathematical Platonism Mathematical platonism is any metaphysical account of mathematics that implies mathematical entities exist, that they are abstract, and that they are independent of all our rational activities. For example, a platonist might assert that the number pi exists outside of space and time and has the characteristics it does regardless of any mental or physical activities of human beings. Mathematical platonists are often

Causation The question, “What is causation?” may sound like a trivial question—it is as sure as common knowledge can ever be that some things cause another, that there are causes and they necessitate certain effects. We say that we know that what caused the president’s death was an assassin’s shot. But when asked why, we will most certainly reply that it is because the latter