A TIMES BOOK OF THE YEAR 2021 'Punchy, funny and invigorating ... Pinker is the high priest of rationalism' Sunday Times 'If you've ever considered taking drugs to make yourself smarter, read Rationality instead. It's cheaper, more entertaining, and more effective' Jonathan Haidt, author of The Righteous Mind In the twenty-first century, humanity is reaching new heights of scientific understanding - and at the same time appears to be losing its mind. How can a species that discovered vaccines for Covid-19 in less than a year produce so much fake news, quack cures and conspiracy theorizing? In Rationality, Pinker rejects the cynical cliché that humans are simply an irrational species - cavemen out of time fatally cursed with biases, fallacies and illusions. After all, we discovered the laws of nature, lengthened and enriched our lives and set the benchmarks for rationality itself. Instead, he explains, we think in ways that suit the low-tech contexts in which we spend most of our lives, but fail to take advantage of the powerful tools of reasoning we have built up over millennia: logic, critical thinking, probability, causal inference, and decision-making under uncertainty. These tools are not a standard part of our educational curricula, and have never been presented clearly and entertainingly in a single book - until now. Rationality matters. It leads to better choices in our lives and in the public sphere, and is the ultimate driver of social justice and moral progress. Brimming with insight and humour, Rationality will enlighten, inspire and empower. 'A terrific book, much-needed for our time' Peter Singer

An argument that logic is intrinsically psychological and human psychology is intrinsically logical, and that the connection between human rationality and logic is both constitutive and mutual. In Rationality and Logic, Robert Hanna argues that logic is intrinsically psychological and that human psychology is intrinsically logical. He claims that logic is cognitively constructed by rational animals (including humans) and that rational animals are essentially logical animals. In order to do so, he defends the broadly Kantian thesis that all (and only) rational animals possess an innate cognitive "logic faculty." Hanna's claims challenge the conventional philosophical wisdom that sees logic as a fully formal or "topic-neutral" science irreconcilably separate from the species- or individual-specific focus of empirical psychology.Logic and psychology went their separate ways after attacks by Frege and Husserl on logical psychologism—the explanatory reduction of logic to empirical psychology. Hanna argues, however, that—despite the fact that logical psychologism is false—there is an essential link between logic and psychology. Rational human animals constitute the basic class of cognizers or thinkers studied by cognitive psychology; given the connection between rationality and logic that Hanna claims, it follows that the nature of logic is significantly revealed to us by cognitive psychology. Hanna's proposed "logical cognitivism" has two important consequences: the recognition by logically oriented philosophers that psychologists are their colleagues in the metadiscipline of cognitive science; and radical changes in cognitive science itself. Cognitive science, Hanna argues, is not at bottom a natural science; it is both an objective or truth-oriented science and a normative human science, as is logic itself.

How to assess critical aspects of cognitive functioning that are not measured by IQ tests: rational thinking skills. Why are we surprised when smart people act foolishly? Smart people do foolish things all the time. Misjudgments and bad decisions by highly educated bankers and money managers, for example, brought us the financial crisis of 2008. Smart people do foolish things because intelligence is not the same as the capacity for rational thinking. The Rationality Quotient explains that these two traits, often (and incorrectly) thought of as one, refer to different cognitive functions. The standard IQ test, the authors argue, doesn't measure any of the broad components of rationality—adaptive responding, good judgment, and good decision making. The authors show that rational thinking, like intelligence, is a measurable cognitive competence. Drawing on theoretical work and empirical research from the last two decades, they present the first prototype for an assessment of rational thinking analogous to the IQ test: the CART (Comprehensive Assessment of Rational Thinking). The authors describe the theoretical underpinnings of the CART, distinguishing the algorithmic mind from the reflective mind. They discuss the logic of the tasks used to measure cognitive biases, and they develop a unique typology of thinking errors. The Rationality Quotient explains the components of rational thought assessed by the CART, including probabilistic and scientific reasoning; the avoidance of “miserly” information processing; and the knowledge structures needed for rational thinking. Finally, the authors discuss studies of the CART and the social and practical implications of such a test. An appendix offers sample items from the test.

Rationality and freedom are among the most profound and contentious concepts in philosophy and the social sciences. In this, the first of two volumes, Amartya Sen brings clarity and insight to these difficult issues.

Prevailing economic theory presumes that agents act rationally when they make decisions, striving to maximize the efficient use of their resources. Psychology has repeatedly challenged the rational choice paradigm with persuasive evidence that people do not always make the optimal choice. Yet the paradigm has proven so successful a predictor that its use continues to flourish, fueled by debate across the social sciences over why it works so well. Intended to introduce novices to rational choice theory, this accessible, interdisciplinary book collects writings by leading researchers. The Limits of Rationality illuminates the rational choice paradigm of social and political behavior itself, identifies its limitations, clarifies the nature of current controversies, and offers suggestions for improving current models. In the first section of the book, contributors consider the theoretical foundations of rational choice. Models of rational choice play an important role in providing a standard of human action and the bases for constitutional design, but do they also succeed as explanatory models of behavior? Do empirical failures of these explanatory models constitute a telling condemnation of rational choice theory or do they open new avenues of investigation and theorizing? Emphasizing analyses of norms and institutions, the second and third sections of the book investigate areas in which rational choice theory might be extended in order to provide better models. The contributors evaluate the adequacy of analyses based on neoclassical economics, the potential contributions of game theory and cognitive science, and the consequences for the basic framework when unequal bargaining power and hierarchy are introduced.

Ralph Wedgwood gives a general account of the concept of rationality. The Value of Rationality is designed as the first instalment of a trilogy - to be followed by accounts of the requirements of rationality that apply specifically to beliefs and choices. The central claim of the book is that rationality is a normative concept. This claim is defended against some recent objections. Normative concepts are to be explained in terms of values (not in terms of 'ought' or reasons). Rationality is itself a value: rational thinking is in a certain way better than irrational thinking. Specifically, rationality is an internalist concept: what it is rational for you to think now depends solely on what is now present in your mind. Nonetheless, rationality has an external goal - the goal of thinking correctly, or getting things right in one's thinking. The connection between thinking rationally and thinking correctly is probabilistic: if your thinking is irrational, that is in effect bad news about your thinking's degree of correctness. This account of rationality explains how we should set about giving a theory of what it is for beliefs and choices to be rational. Wedgwood thus unifies practical and theoretical rationality, and reveals the connections between formal accounts of rationality (such as those of formal epistemologists and decision theorists) and the more metaethics-inspired recent discussions of the normativity of rationality. He does so partly by drawing on recent work in the semantics of normative and modal terms (including deontic modals like 'ought').

In Consistency, Choice, and Rationality, economic theorists Walter Bossert and Kotaro Suzumura present a thorough mathematical treatment of Suzumura consistency, an alternative to established coherence properties such as transitivity, quasi-transitivity, or acyclicity. Applications in individual and social choice theory, fields important not only to economics but also to philosophy and political science, are discussed. Specifically, the authors explore topics such as rational choice and revealed preference theory, and collective decision making in an atemporal framework as well as in an intergenerational setting.