Many philosophers believe they can gain knowledge about the world from the comfort of their armchairs, simply by reflecting on the nature of things. But how can the mind arrive at substantive knowledge of the world without seeking its input? Michael Strevens proposes an original defense of the armchair pursuit of philosophical knowledge, focusing on “the method of cases,” in which judgments about category membership—Does this count as causation? Does that count as the right action to take?—are used to test philosophical hypotheses about such matters as causality, moral responsibility, and beauty.

Strevens argues that the method of cases is capable of producing reliable, substantial knowledge. His strategy is to compare concepts of philosophical things to concepts of natural kinds, such as water. Philosophical concepts, like natural kind concepts, do not contain the answers to philosophers’ questions; armchair philosophy therefore cannot be conceptual analysis. But just as natural kind concepts provide a viable starting point for exploring the nature of the material world, so philosophical concepts are capable of launching and sustaining fruitful inquiry into philosophical matters, using the method of cases. Agonizing about unusual “edge cases,” Strevens shows, can play a leading role in such discoveries.

Thinking Off Your Feet seeks to reshape current debates about the nature of philosophical thinking and the methodological implications of experimental philosophy, to make significant contributions to the cognitive science of concepts, and to restore philosophy to its traditional position as an essential part of the human quest for knowledge.

In this forcefully argued book, the leading evolutionary theorist of language draws on evidence from evolutionary biology, genetics, physical anthropology, anatomy, and neuroscience, to provide a framework for studying the evolution of human language and cognition.

Philip Lieberman argues forcibly that the widely influential theories of language's development, advanced by Chomskian linguists and cognitive scientists, especially those that postulate a single dedicated language "module," "organ," or "instinct," are inconsistent with principles and findings of evolutionary biology and neuroscience. He argues that the human neural system in its totality is the basis for the human language ability, for it requires the coordination of neural circuits that regulate motor control with memory and higher cognitive functions. Pointing out that articulate speech is a remarkably efficient means of conveying information, Lieberman also highlights the adaptive significance of the human tongue.

Fully human language involves the species-specific anatomy of speech, together with the neural capacity for thought and movement. In Lieberman's iconoclastic Darwinian view, the human language ability is the confluence of a succession of separate evolutionary developments, jury-rigged by natural selection to work together for an evolutionarily unique ability.

If children were little scientists who learn best through firsthand observations and mini-experiments, as conventional wisdom holds, how would a child discover that the earth is round—never mind conceive of heaven as a place someone might go after death? Overturning both cognitive and commonplace theories about how children learn, Trusting What You’re Told begins by reminding us of a basic truth: Most of what we know we learned from others.

Children recognize early on that other people are an excellent source of information. And so they ask questions. But youngsters are also remarkably discriminating as they weigh the responses they elicit. And how much they trust what they are told has a lot to do with their assessment of its source. Trusting What You’re Told opens a window into the moral reasoning of elementary school vegetarians, the preschooler’s ability to distinguish historical narrative from fiction, and the six-year-old’s nuanced stance toward magic: skeptical, while still open to miracles. Paul Harris shares striking cross-cultural findings, too, such as that children in religious communities in rural Central America resemble Bostonian children in being more confident about the existence of germs and oxygen than they are about souls and God.

We are biologically designed to learn from one another, Harris demonstrates, and this greediness for explanation marks a key difference between human beings and our primate cousins. Even Kanzi, a genius among bonobos, never uses his keyboard to ask for information: he only asks for treats.

Tychomancy—meaning “the divination of chances”—presents a set of rules for inferring the physical probabilities of outcomes from the causal or dynamic properties of the systems that produce them. Probabilities revealed by the rules are wide-ranging: they include the probability of getting a 5 on a die roll, the probability distributions found in statistical physics, and the probabilities that underlie many prima facie judgments about fitness in evolutionary biology.

Michael Strevens makes three claims about the rules. First, they are reliable. Second, they are known, though not fully consciously, to all human beings: they constitute a key part of the physical intuition that allows us to navigate around the world safely in the absence of formal scientific knowledge. Third, they have played a crucial but unrecognized role in several major scientific innovations.

A large part of Tychomancy is devoted to this historical role for probability inference rules. Strevens first analyzes James Clerk Maxwell’s extraordinary, apparently a priori, deduction of the molecular velocity distribution in gases, which launched statistical physics. Maxwell did not derive his distribution from logic alone, Strevens proposes, but rather from probabilistic knowledge common to all human beings, even infants as young as six months old. Strevens then turns to Darwin’s theory of natural selection, the statistics of measurement, and the creation of models of complex systems, contending in each case that these elements of science could not have emerged when or how they did without the ability to “eyeball” the values of physical probabilities.