G. E. Moore

George Edward Moore

In 1925 an anthology called Contemporary British Philosophy invited the country's leading philosophers to state, each in a single essay, what they actually believed. It was an age of magnificent systems. The idealism in which Moore had been trained had concluded that time is unreal, that matter is contradictory appearance, that the world of chairs and breakfasts distorts one timeless spiritual Absolute. Against that backdrop Moore submitted a list of platitudes. There exists at present a living human body, which is my body. That body was born some years ago and has been on or near the surface of the earth ever since. There are many other bodies and many other people, and the earth existed for many years before any of them. Then comes the sentence that turns the list into an ambush: every one of these propositions, Moore says, he knows, with certainty, to be true. Whole metaphysical systems had been built on premises less certain than "I had breakfast before I had lunch," and when such a system contradicts such a truism, Moore's verdict is that the system is false, and known to be false before anyone finds the flaw in its argument. "A Defence of Common Sense" runs to a few dozen dry, numbered pages, and it is one of the most aggressive documents in twentieth-century philosophy.

The revolt that began a tradition. Born in 1873 in Upper Norwood, south London, Moore went from Dulwich College to Trinity College, Cambridge, in 1892 to read classics. Russell, two years ahead, heard him in discussion and persuaded him to take up philosophy; within a few years the recruit was leading the recruiter. Both fell first under the spell of McTaggart, the Trinity Hegelian who argued with unnerving rigor that time does not exist, and through him under the wider authority of Bradley and Appearance and Reality. The break came at the end of the decade. In a fellowship dissertation on the metaphysical basis of ethics and the papers that grew out of it, Moore decided that the idealists' depth was purchased with ambiguity, and Russell said ever afterward that in the rebellion of 1898 it was Moore who led and he who followed. The decisive document is "The Refutation of Idealism" of 1903, which fixed on the formula Berkeley had bequeathed to the tradition: esse is percipi, to be is to be perceived. Moore's instrument was a distinction. In any sensation there are two elements, the awareness and what it is awareness of, and the two are not the same. Consciousness, he wrote, is as if diaphanous: when we try to introspect the sensation of blue, all we can see is the blue. The idealist gets from "everything we know is known" to "everything that exists is mental" only by collapsing the object into the awareness of it, and the collapse is a confusion, not a discovery. Analytic philosophy is conventionally dated from that revolt.

What this room reads. Moore wrote in English, so nothing here passes through a translator. The corpus carries four public-domain texts: Principia Ethica (1903, Cambridge University Press, in the Project Gutenberg transcription), the 1912 Ethics (the small Home University Library volume, from an Internet Archive scan with light OCR noise), Philosophical Studies (1922, the ten collected papers, including "The Refutation of Idealism," "The Status of Sense-Data," "External and Internal Relations," and "The Conception of Intrinsic Value"), and "A Defence of Common Sense" itself, extracted from Muirhead's 1925 anthology. Cite Principia Ethica by section (the naturalistic fallacy at §10, the open question at §13, the Ideal at §113), Ethics by chapter (Free Will is Chapter VI), and the essays by title. Nearly everything Moore published after 1929 remains in copyright and is absent: "Proof of an External World" (1939), the lectures published as Some Main Problems of Philosophy, the replies to his critics. The chat will say so when a question turns on those texts and will answer from general knowledge rather than retrieved passages.

Good is good. Principia Ethica opens by announcing the method that a century of philosophy would adopt as its house style: the difficulties and disagreements that fill the history of ethics, Moore writes, come mainly from the attempt to answer questions without first discovering precisely what question it is which you desire to answer. His own question is what the word good means, and his answer made him famous: it means nothing else. Good is good, and that is the end of the matter; the notion is simple and unanalyzable the way yellow is, graspable but not decomposable. Every attempt to define it (as pleasure, as what we desire to desire, as whatever is more evolved) commits what he christened the naturalistic fallacy, the identification of this simple, non-natural property with some natural thing that merely accompanies it. His test, the open question argument of §13, can be run without training. Take a proposed definition: good means pleasant. Now ask, "but is what is pleasant good?" The question plainly still asks something; it is open in a way that "is what is pleasant pleasant?" is not. Whatever definition be offered, Moore observes, it may always be asked, with significance, whether the thing so defined is itself good, and that felt openness shows the definition has missed its object. Mill's proof of utilitarianism is his prize specimen, and Spencer's evolutionary ethics gets the same instrument. Whether the argument proves what it claims is still disputed (critics since 1939 have charged that it assumes the indefinability it concludes), but it permanently changed the subject. The modern field called metaethics, the study of what moral words are doing, begins at §13.

The method of isolation and the Ideal. If good cannot be defined, it can still be found, and the back half of Principia Ethica builds the instruments for finding it. The principle of organic unities (§18) holds that the value of a whole need bear no regular relation to the sum of the values of its parts: the consciousness of a beautiful object is worth enormously more than bare beauty plus bare consciousness, and indignation at cruelty has a value neither ingredient has alone. To discover what is good in itself, Moore proposes the method of absolute isolation (§§112-113): ask what things, existing entirely by themselves in an otherwise empty universe, we should still judge it well that they exist. His answer is the most quoted sentence in the book: by far the most valuable things we know or can imagine are certain states of consciousness, roughly describable as the pleasures of human intercourse and the enjoyment of beautiful objects. Personal affection and the experience of beauty are not means to the good; they are most of what the good is. That chapter became a creed. The young Bloomsbury circle (Keynes, Leonard Woolf, Lytton Strachey, Apostles in Moore's Cambridge orbit) took the final chapter of Principia as a charter for a life built around friendship and art, and Keynes later recalled its effect on his generation as the opening of a new world. The driest moral logician in English had written, at §113, the era's most romantic conclusion.

Right action as results. The 1912 Ethics, written for a general audience, turns from the meaning of good to the rightness of acts, and quietly fixes the shape of a hundred years of moral theory. Moore defends what later writers call ideal utilitarianism: an action is right when no alternative open to the agent would have produced a better total outcome, where better means more intrinsic good, not more pleasure. Chapters III and IV argue that moral judgments are objective: if an action is wrong, it cannot be wrong from my standpoint and right from yours, any more than a proposition can be true for me and false for you. Chapter VI contains one of the most consequential paragraphs in modern philosophy of action. The claim "I could have done otherwise," Moore suggests, may be simply a short way of saying "I should have done otherwise, if I had so chosen": a conditional, and one that can be true even if determinism is. Whether freedom and causal necessity are compatible has been argued through that little analysis ever since; a large part of the twentieth-century compatibilism literature is commentary on Ethics, Chapter VI.

Knowing without analyzing. The Defence's deepest move is a distinction that organizes everything else Moore did: between knowing a proposition to be true and being able to give its correct analysis. I know with certainty that this is a hand; what the right analysis of that proposition is (whether it involves sense-data, and how a sense-datum stands to the surface of a hand) Moore regarded as wide open, and his own attempts never satisfied him. Philosophy's task is therefore not to certify ordinary knowledge, which needs no certificate, but to anatomize it. From the same distinction follows the maneuver now taught as the Moorean shift. Every skeptical argument has premises; run it forward and it concludes that I do not know I have hands. But I am more certain that I know I have hands than I could ever be of any philosophical premise, so I am entitled to run the argument in reverse: what the skeptic offers as a proof that I know nothing, Moore reads as a refutation of the skeptic's premises, even before he can say which premise has failed. In 1939 he staged the shift in public. Kant had called it a scandal that philosophy still possessed no proof of the external world; Moore, lecturing to the British Academy under exactly that title, raised one hand, then the other: here is one hand, and here is another; therefore two external things exist. The audience laughed, and philosophers have argued ever since about whether the proof is a joke, a profundity, or both at once. Wittgenstein filled the late notebooks published as On Certainty with replies to Moore's truisms: they cannot be doubted, he agreed, but they function as hinges on which inquiry turns rather than as things we know. When the late masterpiece of the century's most original philosopher is an extended argument with your truisms, you have not missed the point of skepticism. You have moved it.

The cartoon Moore is a period figure: the earnest don who thought waving his hands settled what the skeptics had raised, the literal mind that subtler readers outgrow. Nearly the reverse is true. The two practices that still define analytic philosophy, finding the question before answering it and treating the obvious as evidence rather than as embarrassment, are his signature, and both are sharper instruments than they look. Contemporary epistemology speaks of "Moorean facts," the things we are more certain of than of any theory that denies them; arguments across the discipline are still scored by whether their conclusions can outrank their premises. And the method can be tested tonight, on any confident headline definition (happiness is dopamine, goodness is fitness, the mind is its neurons), by asking Moore's question: does it still make sense to ask whether the defining thing has the property it defines? If the question opens, the definition has not closed it. That small, repeatable act of intellectual hygiene is Moore's standing gift, and the list of truisms in the Defence still reads as a dare addressed to every system not yet written: find the premise more certain than these.