Experiments in Ethics

Kwame Anthony Appiah

• Éditeur: Harvard University Press
• Année: 2010
• ISBN:
  9780674252028
• Sujet: Philosophy
• Sous-sujet: Ethics & Moral Philosophy

In the past few decades, scientists of human nature—including experimental and cognitive psychologists, neuroscientists, evolutionary theorists, and behavioral economists—have explored the way we arrive at moral judgments. They have called into question commonplaces about character and offered troubling explanations for various moral intuitions. Research like this may help explain what, in fact, we do and feel. But can it tell us what we ought to do or feel? In Experiments in Ethics, the philosopher Kwame Anthony Appiah explores how the new empirical moral psychology relates to the age-old project of philosophical ethics.Some moral theorists hold that the realm of morality must be autonomous of the sciences; others maintain that science undermines the authority of moral reasons. Appiah elaborates a vision of naturalism that resists both temptations. He traces an intellectual genealogy of the burgeoning discipline of "experimental philosophy, " provides a balanced, lucid account of the work being done in this controversial and increasingly influential field, and offers a fresh way of thinking about ethics in the classical tradition.Appiah urges that the relation between empirical research and morality, now so often antagonistic, should be seen in terms of dialogue, not contest. And he shows how experimental philosophy, far from being something new, is actually as old as philosophy itself. Beyond illuminating debates about the connection between psychology and ethics, intuition and theory, his book helps us to rethink the very nature of the philosophical enterprise.

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Introduction: The Waterless Moat

The study of history confirms the reasonings of true philosophy.

—DAVID HUME, A Treatise of Human Nature

The Partition

At least since Homer, in the European tradition—but surely everywhere and everywhen in societies both oral and literate—communities have fashioned themselves around stories of the past, chronicles that constitute “us” as Hellenes or Yorubas or Americans. This is, by now, a familiar idea, famously expressed more than a century ago by Ernest Renan in his essay “Qu’estce qu’une nation?” (What Is a Nation?) It is not as often remarked that the communities that engage in this practice are not just ethnic and national: one of my communities, the league of Western philosophers, has constructed histories that reach back two and a half millennia, assigning to the ancients the very problems we now claim to be working through ourselves.

“Forgetting, and I would even say historical error, is an essential element in the creation of a nation,” Renan noticed, rather more provocatively, “and that is why the progress of historical studies is often a danger for the nation itself.”¹ His observation could just as easily have been made about disciplines: there is the same likelihood of forgetting and historical error here, too. Offering an account of the past, in disciplinary histories as in ethnic and national ones, is in part a way of justifying a contemporary practice. And once we have a stake in a practice, we shall be tempted to invent a past that supports it. Disciplines are shaped by what Kant once called the conflict of the faculties—the struggle among the different traditions associated with different departments. And, in those conflicts, incompatible stories are often told about how we got to be where we are. If they are incompatible, one of them must be wrong. So we can agree with Renan both that such conflicts are constitutive (“essential,” as he says) and that the truth (the “progress of historical studies”) may be threatening.

It’s often said that psychology has a short history and a long past. Might the opposite be true of philosophy? In what follows I want to invert some common assumptions about the continuity of my discipline. Philosophy is now typically defined by what it is not (psychology, physics, anthropology, etc.), and if you want philosophers to engage more eagerly with practitioners of other disciplines, it’s helpful to see how newfangled that disciplinary self-conception really is. What’s novel isn’t the experimental turn; what’s novel was the turn away from it.

Looking back at our putative ancestors with an attempt at historical objectivity, one is struck by how much of what Renan called “forgetting” the construction of a philosophical canon has required. We have had to ignore so much of what they wrote. Plato and Aristotle had almost physiological theories about the nature of the soul and the nature of life, which invoked reason and various kinds of passions to explain the way people behave and more general faculties, shared between humans and other animals, to explain, say, the workings of the senses.

Is Descartes, whose “mechanical philosophy” aimed to overturn Aristotelianism, our true forebear? Then you should wonder at how selectively most of us read him. Much of his attention, after all, was devoted to geometry and optics, and for a period, he was revered among scholars as, principally, a sort of mathematical physicist. (The only reference to him you will almost certainly know of, if you don’t do philosophy, is in talk of the “Cartesian” coordinates he pioneered.) He also spent time and energy dissecting cows and other animals. Only later was he repositioned as, centrally, a theorist of mind and knowledge, whose primary concern had to do with the justification of belief. In his The Passions of the Soul (1649), he discusses the way the “movements of the muscles, and likewise all sensations, depend on the nerves, which are like little threads or tubes coming from the brain and containing, like the brain itself, a certain very fine air or wind which is called the ‘animal spirits.’”² Descartes aimed to solve what we think of as the canonically philosophical puzzle about the relation between the soul and the body by appeal to an empirical hypothesis about the brain: “On carefully examining the matter, I think I have clearly established that the part of the body in which the soul directly exercises its functions is . . . the innermost part of the brain, which is a certain very small gland situated in the middle of the brain’s substance and suspended above the passage through which the spirits in the brain’s anterior cavities communicate with those in its posterior cavities.”³ That “very small” gland (the pineal, which sits near the hypothalamus) is not an incident of the theory. Without it, Descartes has no story of how mind and body are functionally integrated.

“The true philosophy,” Robert Hooke wrote in his Micrographia (1665), is “to begin with the Hands and Eyes, and to proceed on through the Memory, to be continued by the Reason; nor is it to stop there, but to come about to the Hands and Eyes again, and so, by a continual passage round from one Faculty to another, it is to be maintained in life and strength, as much as the body of man is by the circulation of the blood through the several parts of the body, the Arms, the Feet, the Lungs, the Heart, and the Head.”⁴ It’s a lovely image—but he was simply describing what he took to be the basis of any sound learning. The term “philosophy” hewed to the curricular contours of the medieval university, in which it was a general designation for systematic knowledge, typically subdivided into the natural, moral, and metaphysical (the last—in the scholastic mode—being largely confined to typologies of substance and accidents, form and matter).

I don’t want to overstate the case: before the disciplinary rise of modern philosophy, one can readily trace distinctions—between, say, reason and experience, speculation and experiment—that seem cognate to our way of organizing knowledge. When Thomas Hobbes denied that Robert Boyle’s air-pump research deserved the name “philosophy,” one element of his brief was the intrinsic superiority of demonstrative findings (à la Euclid) to experimental findings. But another was simply that the pump was leaky.⁵ Descartes gives us hope when he refers to “first philosophy,” and he famously maintained that “all philosophy is like a tree, of which the roots are metaphysics, the trunk is physics, and the branches, which grow from this trunk, are all of the other sciences, which is to say medicine, mechanics, and morals.”⁶ Yet even here, we can see that his taxonomy isn’t quite ours: morals, to us a division of philosophy, is to him a practical endeavor on a par with medicine. Margaret Cavendish, early in her Observations upon Experimental Philosophy (1668), urged that “the experimental part of philosophy” was not to be “preferred before the speculative,” for “most experiments have their rise from the speculative, so the artist or mechanic is but a servant to the student.”⁷ Still, it’s significant that, at the time, there were virtually no thinkers who confined themselves to the realm of unsullied abstraction; Cavendish, in later chapters of her Observations, went on to offer opinions about how wood got petrified and whether snails have blood. John Locke’s inquiries into the origins of ideas involved consideration of facts about savages and children.

By the eighteenth century, the growing prestige of experimentation was apparent everywhere. The encyclopedist Jean D’Alembert praised Locke for reducing metaphysics to what it should be: “la physique expérimentale de l’âme”—the experimental science of the spirit.⁸ And Hume subtitled his great Treatise of Human Nature, as we do not sufficiently often recall, Being an Attempt to Introduce the Experimental Method of Reasoning into Moral Subjects. The point is not just that the canonical philosophers belong as much to the history of what we now call psychology as to the genealogy of philosophy. It is that their “metaphysical” and their psychological claims are, insofar as we insist on distinguishing them, profoundly interdependent. Their proper place as ancestors of both modern disciplines is reflected in the fact that many of the claims they make about the mind—including those claims that are thought to be of current philosophical relevance—are founded in empirical observation, even if they are not often founded in experiment. They depend on stories about the actual doings of actual people, on claims about how humanity actually is. Hume’s History of England—five volumes of empirical information, elegantly organized—has rightly been seen as expressing ideas about morality and politics and psychology. For him, it was an extension of the project of a work like the Enquiry concerning Human Understanding, where, in a famous footnote, Hume identified and rebutted an emerging tendency:

NOTHING is more usual than for writers, even, on moral, political, or physical subjects, to distinguish between reason and experience, and to suppose, that these species of argumentation are entirely different from each other. The former are taken for the mere result of our intellectual faculties, which, by considering a priori the nature of things . . . establish particular principles of science and philosophy. The latter are supposed to be derived entirely from sense and observation, by which we learn what has actually resulted from the operation of particular objects . . .

But notwithstanding that this distinction be thus universally received, both in the active and speculative scenes of life, I shall not scruple to pronounce, that it is, at bottom, erroneous, at least, superficial. . . . It is experience which is ultimately the foundation of our inference and conclusion.⁹

A case has been made that the modern conception of the discipline is presaged in the epistemological preoccupations of Thomas Reid and Immanuel Kant.¹⁰ But Reid himself was emphatic in his suspicion of mere conjecture. Every real discovery, he says, is arrived at by “patient observation, by accurate experiments, or by conclusions drawn by strict reasoning from observation and experiments, and such discoveries have always tended to refute, but not to confirm, the theories and hypotheses which ingenious men had invented.”¹¹

It is anything but historically anomalous that Kant, to whom we owe the analytic-synthetic distinction, worked avidly on both sides of the putative divide. The founder of “critical philosophy” elaborated theories of the winds and of the earth’s rotation, and dispensed advice about the training of the young (“games with balls are among the best for children”); the author of A Critique of Pure Reason was also the author of Concerning the Volcanoes on the Moon.¹² Kant possessed the resources for a conceptual partition between what we think of as philosophy and psychology, but not those for a vocational partition.

One artifact of philosophy’s striking modernity—it is almost too obvious to remark—is that twentieth-century reference books almost invariably give pre-twentieth-century philosophers compound designations: this person is a philosopher and mathematician, that a philosopher and littérateur, the other a philosopher and political economist. The trailing conjunction signals the shrunken disciplinary rump state to which we have retreated. To retrace the old boundaries, we might give particular attention to books that call themselves histories of philosophy, because, as Renan would have expected, the contours of the discipline are shaped by such narratives. In this sense, the history of philosophy is the history of its histories. Thomas Stanley’s History of Philosophy (its four volumes, published in the 1650s and 1660s, “containing those on whom the attribute of Wise was conferred”) focused entirely on “barbaric” and classical figures; Jacob Brucker’s Historica Critica Philosophiae, from the 1740s, included, in its survey of modern philosophers, the natural philosophy of Copernicus, Kepler, Galileo, Newton, and so on. Hegel’s Lectures on the History of Philosophy (published in 1832, a year after his death) contained the now-commonplace distinction between rationalism and empiricism, but placed Locke together with Descartes in the first camp. And though Hegel chastised Newton for his dictum “Physics, beware of metaphysics,” it was in part because he thought that this led to bad science: “Regarding matters as he did, Newton derived his conclusions from his experiences; and in physics and the theory of color-vision, he made bad observations and drew worse conclusions. . . . A miserable kind of experience like this itself contradicts itself through nature, for nature is more excellent than it appears in this wretched experience: both nature itself and experience, when carried a little further, contradict it. Hence, of all the splendid discoveries of Newton in optics, none now remain excepting one—the division of light into seven colours.”¹³ (The point is not that Hegel is right, here: it is that these remarks reveal his sense of disciplinary geography.) Even through much of the nineteenth century, by which time physics was a well-defined separate profession, you could routinely replace the term “philosophy” with “philosophy and psychology” without loss of precision.

About a decade after Hegel’s Lectures appeared, and about the same time that George Henry Lewes was publishing his immensely popular Biographical History of Philosophy, Charles Dickens was publishing his novel Martin Chuzzlewit and taking gleeful notice of the ways of self-improving Americans:

“What course of lectures are you attending now, ma’am?” said Martin’s friend, turning again to Mrs. Brick.

“The Philosophy of the Soul, on Wednesdays.”

“On Mondays?”

“The Philosophy of Crime.”

“On Fridays?”

“The Philosophy of Vegetables.”¹⁴

The novelist knew that the term “philosophy” breathed uplift, whatever its purview (which he only slightly exaggerated). The historical ambit of the noun, plainly, is no more a guide to its current disciplinary contours than the Macedonian empire is to the present-day republic of Macedonia. You would have had a difficult time explaining to most of the canonical philosophers that this part of their work was echt philosophy and that part of their work was not. Trying to separate out the “meta-physical” from the “psychological” elements in this corpus is like trying to peel a raspberry.

Psychologism and Anti-Psychologism

Did psychology calve off from philosophy? You can make a strong case that it was the other way around. Hobbes, Locke, and Hume spent a great deal of energy elaborating an account of associationist psychology, in order to explain how faculties of the human mind processed sensations and ideas; for John Stuart Mill, logic was “not a Science distinct from, and co-ordinate with, Psychology. So far as it is a science at all, it is a part, or branch, of Psychology.”¹⁵ It was as a professor of philosophy at the University of Leipzig th...