Modal Logic: A Contemporary View Modal notions go beyond the merely true or false by embedding what we say or think in a larger conceptual space referring to what might be or might have been, should be, or should have been, or can still come to be. Modal expressions occur in a remarkably wide range across natural languages, from necessity, possibility, and contingency to expressions

Charles Sanders Peirce: Logic Charles Sanders Peirce (1839-1914) was an accomplished scientist, philosopher, and mathematician, who considered himself primarily a logician. His contributions to the development of modern logic at the turn of the 20th century were colossal, original and influential. Formal, or deductive, logic was just one of the branches in which he exercized his logical and analytical talent. His work developed upon Boole’s

David Hume: Imagination David Hume (1711–1776) approaches questions in epistemology, metaphysics, ethics and aesthetics via questions about our minds. For example, before addressing the epistemological question of whether we have any justification for our beliefs about unobserved states of affairs, Hume asks which of our cognitive faculties is responsible for these beliefs. Before addressing the metaphysical question, What is causal necessity (or necessary connexion)? , he

Dualism and Mind Dualists in the philosophy of mind emphasize the radical difference between mind and matter. They all deny that the mind is the same as the brain, and some deny that the mind is wholly a product of the brain. This article explores the various ways that dualists attempt to explain this radical difference between the mental and the physical world. A wide

Sablé, Madeleine de Souvré, Marquise De (1598—1678) A prominent salonnière in seventeenth-century Paris, Madame de Sablé has long occupied the background of early modern French philosophy. She has survived in intellectual history as the patron of La Rochefoucauld, as the hostess of a theological salon, and as the correspondent of Blaise Pascal and Antoine Arnauld. These ancillary roles have obscured her original contributions to moral

Moral Development This entry analyzes moral development as a perennial philosophical view complemented by modern empirical research programs. The two initial sections summarize what moral development is and why it is important for ethics and human nature theory. The “Roots” section notes historical versions of natural development in morality, touching on Confucius, Aristotle, Rousseau and Rawls. The next four sections assess current empirical research in