Can OUGHT be derived from IS? This book presents an investigation of this time-honored problem by means of alethic-deontic predicate logic. New in this study is the leitmotif of relevance: is-ought inferences indeed exist, but they are all irrelevant in a precise logical sense. New proof techniques establish this result for very broad classes of logics. A profound philosophical analysis of is-ought bridge principles supplements the logical study. The final results imply incisive limitations for the justifiability of ethics as opposed to empirical science.

This book motivates a novel inferentialist account of the meaning of a core set of normative sentences. Building on a careful truth-conditionalist semantics for 'ought' considered as a modal word, Chrisman argues that ought-sentences mean what they do neither because of how they describe reality nor because of the noncognitive attitudes they express, but because of their inferential role.

If philosophy has any business in the world, it is the clarification of our thinking and the clearing away of ideas that cloud the mind. In this book, one of the world's preeminent philosophers takes issue with an idea that has found an all-too-prominent place in popular culture and philosophical thought: the idea that while factual claims can be rationally established or refuted, claims about value are wholly subjective, not capable of being rationally argued for or against. Although it is on occasion important and useful to distinguish between factual claims and value judgments, the distinction becomes, Hilary Putnam argues, positively harmful when identified with a dichotomy between the objective and the purely "subjective." Putnam explores the arguments that led so much of the analytic philosophy of language, metaphysics, and epistemology to become openly hostile to the idea that talk of value and human flourishing can be right or wrong, rational or irrational; and by which, following philosophy, social sciences such as economics have fallen victim to the bankrupt metaphysics of Logical Positivism. Tracing the problem back to Hume's conception of a "matter of fact" as well as to Kant's distinction between "analytic" and "synthetic" judgments, Putnam identifies a path forward in the work of Amartya Sen. Lively, concise, and wise, his book prepares the way for a renewed mutual fruition of philosophy and the social sciences.

Is it possible to apply a theoretical approach to ethics? The French philosopher Catherine Chalier addresses this question with an unusual combination of traditional ethics and continental philosophy. In a powerful argument for the necessity of moral reflection, Chalier counters the notion that morality can be derived from theoretical knowledge. Chalier analyzes the positions of two great moral philosophers, Kant and Levinas. While both are critical of an ethics founded on knowledge, their criticisms spring from distinctly different points of view. Chalier reexamines their conclusions, pitting Levinas against (and with) Kant, to interrogate the very foundations of moral philosophy and moral imperatives. She provides a clear, systematic comparison of their positions on essential ideas such as free will, happiness, freedom, and evil. Although based on a close and elegant presentation of Kant and Levinas, Chalier's book serves as a context for the development of the author's own reflections on the question "What am I supposed to do?" and its continued importance for contemporary philosophy.

Sam Harris dismantles the most common justification for religious faith--that a moral system cannot be based on science.