A Defence of Common Sense

The article was published in 1925, well before Ayer or Austin. Both Ayer and Austin, I think, would take themselves to have absorbed Moore's chief lesson, which is that it is just not on to entertain any serious doubt about common sense knowledge of the world we live in. Austin's methods, in some respects, might be taken to build on some of Moore's. I'm not sure Moore would think Ayer had respected his points.

Moore's motivations are subject to many interpretations. What follows is mine.

Moore begins with a rather peculiar expression of the view that most of us know that we live as embodied human beings in a physical world in which there are other human beings most of whom know those things as well, and that most of us know things not only about the physical world, but also about people, and some of their distinctively human characteristics and know that many other people also know such things. In particular, what he says seems a rather roundabout way of saying that we have (in terms Ayer uses) knowledge of the external world and knowledge of other minds.

So, why the roundabout and long-winded expression of what I just managed to say in a single sentence? Moore does so, in part, because he wants to express knowledge claims that are entirely free of any philosophical jargon (like "external world" and "other minds"). Such terms are used by different philosophers in different ways. The ordinary things he says are not usually explicitly subjected to peculiar philosophical definitions, and so he can use them without having to concern himself with the vagaries of particular philosophical interpretations. Why is the list as long as it is? For each item on the list, there is at least one philosophical point that has been made by at least one philosopher that requires some item of that sort.

Why doesn't Moore mention particular philosophers with whom he takes himself to be disagreeing? It is because his topic is not whether particular philosophers have gotten particular points correct, but rather about some general facts that he thinks should constrain all philosophy. One of Moore's important goals as a philosopher was to exterminate idealism. Not just Berkeley and his British followers whose study had annoyed Moore so much in school, but to make sure that nothing like that ever plagued philosophy again. To mention particular philosophers would have made that goal easier to ignore.

The second reason Moore goes to great lengths to express his knowledge claims without any philosophical jargon has to do with what he takes to be the important grounds on which he knows that those things he claims to know are true: He doesn't give a "philosophical" argument for their truth in the way in which someone might by attempting to counter the arguments of, say, Berkeley. His point is that "everyone" knows that those things are true, where, by everyone, I mean to include the inhabitants of the local bar. One feature of the views of the philosophers he is opposing is that they distinguish the ordinary or popular understanding of various claims with the philosophical. He is, at least implicitly, making the point that (in terms that echo Austin) words like "know" and "body" and "people" are very ordinary words that have plain meanings. To make claims that go against what everyone knows is just to misuse the words in the claim.

We all know that people lived before we were born. If any philosopher claims that we do not know that, that simply shows that that philosopher has made a mistake, perhaps about how the word "know" is used, perhaps about something else in the claim. To claim that we don't know that people lived before we were born is so absurd that claiming it shows that the claim is not about knowledge, which is a very ordinary notion, but about some philosophical variant of knowledge, and it is then not at all clear why we should care, and, if our topic is knowledge, we shouldn't care.

There are certain things we all know, believe, accept, and they cannot be ignored by a philosophical attempt to account for ordinary notions like knowledge, belief, truth. That is, it is a sufficient proof that a philosophical theory is wrong that it goes against common sense in the kinds of cases Moore considers. (Of course, "common sense" is itself often abused into a philosophical term, and so the simple declaration that no philosophical theory can go against common sense can properly make the point.)

He goes on to make a number of number of important points based on recognition of his list of truths. First, every philosopher, even those who have claimed to deny items on his list, knows them and explicitly makes use of them. Thus, some philosophers take themselves to disagree with Moore about items on his list. None do. Every philosopher, in fact (though perhaps not as a matter of principle) makes it clear that she believes every item on the list. Philosophers who disagree with Moore about the items do so by also believing things incompatible with the truth of items on the list. Any time a philosopher mentions the work of another philosopher or talks about common beliefs, that philosopher has admitted that he knows that there is an external world and that there are other persons. Even philosophers who profess to deny either of those facts, while writing, mention other philosophers, and so show that they know them. It would, Moore thinks, in principle be possible to present an internally coherent version of the view that there are no other minds or an external world. One would simply have to never mention any such things.

The way philosophers have in fact denied knowledge of other minds and an external world has always, in fact, been self defeating. One way for an argument to be self defeating is for it to contradict itself. Another way is for it not to be expressible without also assuming, perhaps implicitly, that its conclusions are false.

There is a metaphysical and an epistemological version of most kinds of skepticism: one can deny that, for example, there is an external world (metaphysical), or one can deny that, for example, anyone knows whether or not there is an external world (epistemological). The usual view is that the metaphysical skeptic is making a stronger claim, one that harder to defend, than is the epistemological skeptic. After all, if there is no external world, then it follows that no one knows that there is an external world. Moore points out that, at least in principle, one could coherently express metaphysically skeptical views, but that epistemological skepticism is not merely self defeating, but actually self contradictory: * No one knows that there are other minds. The "no one" part of that sentence presupposes that there are other minds who don't know that. The very expression of the view requires admitting that the view is false.

Moore also makes a point (and this is where I think he would take Ayer to have gone wrong) that many philosophers have denied that they are denying the plain facts Moore lists, but only by reinterpreting the sentences Moore used to say something else.

For example, according to Carnap, to say that something, say dinosaurs, existed in the distant past is just to say that we have present evidence that leads us to believe that there were dinosaurs. In saying that, by Moore's lights, he is making it clear that he doesn't really think that dinosaurs existed in the distant past. If he did, then he would take "dinosaurs existed in the distant past" to mean that dinosaurs existed in the distant past, not something about fossils. Similarly, although I'm on weaker ground here, Ayer takes, "there is a desk in the room" to mean, in sense-datum language, that "were I to enter the room I would see sense data of the sort taken to be produced by a desk" and an infinite collection of like sentences. As Moore says (51), such questions as "Do you believe that the earth has existed for many years past?" are "plain questions," "the very type of unambiguous expressions."

Moore makes a very simple, very important, rarely respected distinction between "understanding its meaning" with "knowing what it means" for each of his common sense claims. Most of us do understand them. However, to know what an expression means is to give an account of its meaning, to give, Moore says, an analysis. It is an absolutely familiar fact that most of us know how to produce grammatical sentences without having the foggiest idea of any relevant grammatical rules. Moore's position is an analogous one for meaning. We understand the ordinary sentences perfectly well, but that does not mean that we can say what it is that they mean. Moore takes it to be a common philosophical mistake (and he is right, and it is still a common philosophical mistake) to trust ones analysis of a statement over ones understanding of it. That is how, for example, idealists can talk themselves into denying that they know that their hand is in front of their face: they have an analysis of knowing from which it follows it that they don't know that. They trust they analysis and draw the conclusion without stopping to realize that, whatever knowing is, we know perfectly well when our hand is in front of our face. They, bizarrely, let the analysis defeat the understanding.

Since that is a central part of what Moore is trying to say in the article, it is incumbent on him to express his view in a way that doesn't rely on any analysis. That is the central reason for the peculiarly irritating style of relying on lists of examples without ever telling us of what they are examples.

Some philosophers (perhaps including Ayer) have taken themselves to know that the truth of items on the list in some way requires the truth or knowledge of various "mental facts." Ayer, for example, takes himself to know that to know that there is a desk, one must have known various facts about sense data. Moore is very careful not to deny that it may in fact be the case that anyone who knows an item on the list also knows some "mental facts." What he does deny is that anyone knows that to know any of the items on the list is to know some "mental fact." He points out that many of the facts on the list could have been true (and we know that they could have been true) even if there were no mental facts. For example, the earth could have existed for many years past even if no people had ever existed.

-- ShaughanLavine - 19 Apr 2007