Carl Gustav Hempel (1905—1997) Carl Hempel, a German-born philosopher who immigrated to the United States, was one of the prominent philosophers of science in the twentieth century. His paradox of the ravens—as an illustration of the paradoxes of confirmation—has been a constant challenge for theories of confirmation. Together with Paul Oppenheim, he proposed a quantitative account of degrees of confirmation of hypotheses by evidence. His

Thomas Aquinas: Moral Philosophy The moral philosophy of St. Thomas Aquinas (1225-1274) involves a merger of at least two apparently disparate traditions: Aristotelian eudaimonism and Christian theology. On the one hand, Aquinas follows Aristotle in thinking that an act is good or bad depending on whether it contributes to or deters us from our proper human end—the telos or final goal at which all human actions aim.

Naturalism Naturalism is an approach to philosophical problems that interprets them as tractable through the methods of the empirical sciences or at least, without a distinctively a priori project of theorizing. For much of the history of philosophy it has been widely held that philosophy involved a distinctive method, and could achieve knowledge distinct from that attained by the special sciences. Thus, metaphysics and epistemology

Diels-Kranz Numbering System Of the writings of the Presocratics, only quotations embedded in the works of later authors have survived. These quotations, along with reports about the Presocratics and imitations of their works, were first compiled into a standard edition (Die Fragmente der Vorsokratiker) in the nineteenth century by Hermann Diels (1848-1922) with revisions by Walther Kranz and subsequent editors, in a complete edition of

Demonstratives and Indexicals In the philosophy of language, an indexical is any expression whose content varies from one context of use to another. The standard list of indexicals includes pronouns such as “I”, “you”, “he”, “she”, “it”, “this”, “that”, plus adverbs such as “now”, “then”, “today”, “yesterday”, “here”, and “actually”. Other candidates include the tenses of verbs, adjectives such as “local”, and a range of