The other day a philosopher of science in a university quite a long way from Oxford asked me whether I thought that "The Ordinary Language Approach to Philosophy" had anything to contribute to the Philosophy of Science. Finding this question difficult to handle for more than one reason, I eventually asked him what he meant by "The Ordinary Language Approach to Philosophy." He replied that he had been hoping that I would not ask that question, as he did not know much about the matter. Perhaps he thought that the reference of this phrase ought to have been immediately clear to me, since it was intended merely to pick out the sort of philosophizing in which I myself (and others at Oxford) habitually engage. Unfortunately I do not find it by any means easy to give a general characterization of the philosophizing in which I engage; indeed I am not sure that it is all of one sort; moreover, I am sure that one could find numerous methodological divergences among Oxford philosophers, though there does, no doubt, also exist a noticeable family resemblance. Again, difficult as it may be to characterize one's own philosophical performance, I was faced with a further difficulty, for I strongly suspected that his idea of my variety of philosophizing might not coincide with the reality. So I shall devote myself here to an attempt (necessarily schematic and fragmentary) to get clearer about my conception of the relation between my own philosophical practice and ordinary language. You must understand that I am speaking on behalf of no one but myself, even though it may well be the case that some philosophers, both in and out of Oxford, might be ready to agree in greater or lesser degree with what I have to say.First of all, it is certainly true that I am not alone in thinking that ordinary discourse, what we ordinarily say, is worthy of the philosopher's special attention. But to say this is not to say very much. To be more specific, I will subscribe to two propositions. (1) It is, in my view, an important part, though by no means the whole, of the philosopher's task to analyze, describe, or characterize (in as general terms as possible) the ordinary use or uses of certain expressions or classes of expressions. If I philosophize about the notion of cause, or about perception, or about knowledge and belief, I expect to find myself considering, among other things, in what sort of situations we should, in our ordinary talk, be willing to speak (or again be unwilling to speak) of something as causing something else to happen; or again of someone as seeing a tree; or again of someone as knowing rather than merely believing that something is the case. Particular mention should perhaps be made of the cases in which one tries to find things that would not ordinarily be said at all; for example, in discussing knowledge and belief, one may find it helpful or indeed essential to take note of such linguistic facts as that one may without linguistic impropriety, speak of someone as "firmly believing" some-thing, but not of someone as "firmly knowing" something. Such linguistic facts, or at least the answers to the question why these are linguistic facts, may be of philosophical importance. (2) It is in my view the case that a philosophical thesis which involves the rejection as false, or absurd, or linguistically incorrect, of some class of statements which would ordinarily be made, and accepted as true, in spe-cifiable types of situation is itself almost certain (perhaps quite cer-tain) to be false; though to say that such a thesis is false is not quite to deny that it may have other virtues, for the philosopher who propounds it may be "getting at" some important truth which could be more properly expressed in another way. To reformulate my second proposition in another way: it is almost certainly (perhaps quite cer-tainly) wrong to reject as false, absurd, or linguistically incorrect some class of ordinary statements if this rejection is based merely on philosophical grounds. If, for example, a philosopher advances a philosophical argument to show that we do not in fact ever see trees and books and human bodies, despite the fact that in a variety of familiar situations we would ordinarily say that we do, then our philosopher is almost (perhaps quite) certainly wrong.  Before proceeding, I must briefly protect myself against a crude misconception (of which I am sure that none of you will be guilty).Neither of my two propositions commits me to holding that non-ordinary uses of language are to be prohibited, or even to be disregarded by the philosopher. I do not for one moment suppose that either a nonphilosopher or a philosopher should confine himself to using only expressions with an ordinary use and to using these only in that ordinary way. The only restriction is that a philosopher who uses a technical term should recognize that it is a technical term and therefore stands in need of a special explanation. When one philosopher objects to another philosopher's argument (as sometimes hap-pens) by saying "But that is not an ordinary use of the expression so-and-so" or "But that expression is being used as a technical term," his objection is not to the nonordinary or technical use of the expression but to the use of an expression in a nonordinary way without the necessary explanation, indeed (usually) to the speaker's failing to recognize that he has substituted a nonordinary for an ordinary use.  It is usually a way of making a charge of equivocation.  I will now mention one or two objections that may be raised to my first proposition, that is, to the proposition that it is an important part of the philosopher's task to characterize the ordinary use of lan-guage.  Objection A  "Can your sort of philosophizing be distinguished from a sociological study of people's language habits, which (moreover) you conduct without collecting the empirical evidence on which such a study should be based, without making the polls which would be required?  Alternatively, can what you do be distinguished from lexicography?  Surely philosophy is not either head-counting or dictionary-making." To deal with this double-headed objection, I shall introduce the notion of "conceptual analysis." I am using this expression in such a way that a piece of conceptual analysis is not necessarily a piece of philosophizing, though it is necessarily in certain respects like philo-sophizing. It is a very old idea in philosophy that you cannot ask, in a philosophical way, what something is unless (in a sense) you already know what it is. Plato (I think) recognized that you are not in a position to ask such a philosophical question as "What is justice?" unless, in a sense, you already know what justice is. This idea reappears in new dress when Moore draws a distinction between knowing what an expression means and knowing its analysis. People who ask phil-osophically what justice is already are able to apply the word "jus-tice" and its congener "just" in particular cases; they will be confronted with many sorts of actions, be ready to apply or withhold the word "just" without hesitation, though there will of course be further sorts of actions with regard to which they would be uncertain whether to apply or withhold this adjective. But people who are in this position of being more or less adequately equipped to decide, with regard to particular actions of different kinds, whether they are to be called "just" or not may very well be at a loss if one asks them (or they ask themselves) to give a general account of the distinction between the sorts of actions which they would, and the sorts of actions which they would not, call "just."  I hope it will now be fairly clear what sort of thing I mean by  "conceptual analysis." To be looking for a conceptual analysis of a given expression E is to be in a position to apply or withhold E in particular cases, but to be looking for a general characterization of the types of case in which one would apply E rather than withhold it.  And we may notice that in reaching one's conceptual analysis of E, one makes use of one's ability to apply and withhold E, for the characteristic procedure is to think up a possible general characterization of one's use of E and then to test it by trying to find or imagine a particular situation which fits the suggested characterization and yet would not be a situation in which one would apply E. If one fails, after careful consideration on these lines, to find any such situation, then one is more or less confident that the suggested characterization of the use of E is satisfactory. But one could not test a suggested characterization in this way, unless one relied on one's ability to apply or withhold E in particular cases.  It may further be remarked that expressions for which one may wish to find a conceptual analysis are not necessarily expressions which are directly of concern to philosophy. One might (wanting a conceptual analysis) ask such a question as "What is a battle?"  "What is a game?" "What is reading?" —for it may be by no means clear how one would distinguish battles from skirmishes, campaigns, and wars, or how one would distinguish games from, for example, recreations or sports, or how one would distinguish reading from all of a range of such things as reciting by heart with the pages open before one's eyes. But the nature of battles, games, and reading would not be regarded either by myself or by most people as falling within the subject matter of philosophy. So to practice conceptual analysis isnot necessarily to practice philosophy; some further condition or conditions must be satisfied for a piece of conceptual analysis to count as a piece of philosophy.  We are now in a position to deal directly with this objection. You may regard me, when I engage in a piece of conceptual analysis (whether of a philosophical or nonphilosophical nature), as primarily concerned to provide a conceptual analysis of my own use of a given expression (of course, I may enlist the aid of others in this enterprise).  To reach a conceptual analysis of one's own use of an expression is often extremely difficult, and you must expect most of my discussion about the conceptual analysis of an expression to relate to this diffi-culty. But if I think that I have reached a satisfactory conceptual analysis of my own use, I do not then go on to conduct a poll to see if this analysis fits other people's use of the expression. For one thing, I assume (justifiably, I think) that it does in general fit other people's use, for the expressions with which (as a philosopher) I am normally concerned are pretty commonly used ones; and if a particular expression E was given by some of the people with whom I talk in my daily life a substantially different use from the one which I gave to it, then I should almost certainly have discovered this; one does discover people's linguistic idiosyncrasies. But more important, even if my assumption that what goes for me goes for others is mistaken, it does not matter; my philosophical puzzles have arisen in connection with my use of E, and my conceptual analysis will be of value to me (and to any others who may find that their use of E coincides with mine).  It may also be of value to those whose use of E is different, though different only in minor respects, from mine; but if this is not so, then we have a different use of E, to be dealt with separately, to be subjected to separate conceptual analysis. This we can do if the need arises (since cooperation in conceptual analysis does not demand identity as regards the use of the analyzed expression; I can, with you, attempt the conceptual analysis of your use of an expression, even if your use is different from mine). So conceptual analysis is not a sociological inquiry; the analyst is not interested in percentages.  Nor is conceptual analysis to be identified with lexicography (as I suspect the objector is conceiving of lexicography). I suspect the objector is thinking of dictionaries as providing a particular sort of def-inition, of which an example would be the definition of a father as a male parent. In fact, examination of dictionaries will very soon showa definition of this kind, but I will not press this point. Let us now compare the following two written definitions:  father— male parent awe- —mixture of fear and admiration  (1) could be regarded as indicating to us that the expression "fa-ther" is correctly applied to a person if and only if he is a male parent; equally, correlation (2) could be regarded as indicating to us that the expression "awe" is applied to a state of feeling if and only if it is a mixture of fear and admiration. So far the correlations are alike. But there is an important difference between them. Roughly, anyone who knows the meaning of the expression "male parent," who did not assent at once to the suggestion that someone is correctly called a father if and only if he is a male parent, would be taken not to know the meaning of the expression "father" (as this expression is stan-dardly used) (unless, of course, his refusal is taken as a sign of non-cooperation, of refusal to play). But a person might be unwilling at once to assent to the suggestion that a state of feeling is correctly called "awe" if and only if it is a mixture of fear and admiration, without thereby showing that he just did not know the meaning of  "awe" (did not know how to use it correctly), for he might legitimately wish to see, for example, whether he could think of a situation in which he would be willing to apply the word "awe" even though what he would be applying it to would not be a mixture of fear and admiration. So what the objector conceives of as dictionary definitions give the meaning of the expressions defined in a sense in which conceptual analyses—of which (2) would be an example-do not give the meaning of the expressions analyzed (though no doubt in another sense of "give the meaning," conceptual analyses do give the meaning of the expressions analyzed). This difference is connected closely with the idea that dictionaries are designed for people who wish to learn to use an expression correctly, whereas conceptual analyses (as already pointed out) are not.  I will deal more shortly with one or two other objections.  Objection B  "Ordinary language suffers from various defects which unfit it for conceptual analysis, or at least prevent conceptual analysis, or at least prevent conceptual analysis from achieving any results which areworth the effort involved in reaching them. Such defects are ambigu-ity, misleadingness, vagueness, and the incorporation of mistakes or absurd assumptions."  Let us take the suggested defects one by one. (a) That ordinary expressions are ambiguous (or better, have more than one meaning) is no reason for not subjecting them to conceptual analysis. This duplicity of meaning will either be obvious, in which case the conceptual analysis will be directed to one or more particular senses of an expres-sion, or it will not be obvious, in which case part of the function of the conceptual analysis will be to bring out into the open what is (or might be) regarded as a duplicity of meaning. (b) That an expression is misleading if it means that it is philosophically misleading, namely that one may be tempted to fail to distinguish the character of its use from that of other expressions which are grammatically similar (e.g. fail to distinguish the character of the use of "exist" from that of such expressions as "growl"), is obviously a reason for rather than against engaging in the conceptual analysis of the expression, for conceptual analysis counteracts the tendency to be misled. (c) To say that an expression is vague (in a broad sense of vague) is presumably, roughly speaking, to say that there are cases (actual or possible) in which one just does not know whether to apply the expression or to withhold it, and one's not knowing is not due to ignorance of the facts. For instance one may not know whether or not to describe a particular man as "bald"; and it may be of no help at all to be told exactly how many hairs he has on his head. The fact that there are cases (even lots of cases) where the applicability of an expression E is undecidable in this kind of way may prevent one from providing a neat and tidy conceptual analysis of E; it may prevent one from specifying a set of conditions the fulfillment of which is both necessary and sufficient for correct application of E. But it does not prevent one from giving any sort of conceptual analysis of E; one can include in one's general characterization of the use of E not only the specification of the types of situation to which E would definitely apply or definitely not apply but also the specification of the types of situation with regard to which the applicability of E would be undecidable (without linguistic legis-lation). Moreover, these undecidable cases may yield one information about one's use of E in the decidable cases. To mention an example given by Locke, if Locke's contemporaries had found that Locke could tell them all kinds of intimate details of the life of Nestor (some at least of which could be independently checked), and if they weresatisfied that Locke had not acquired this information by historical research, they might then have hesitated whether or not to say that Locke was the same person as Nestor. If so, they would have been pulled in two directions; consideration of the continuity of memory would have inclined them to say "same person," consideration of the absence of bodily identity would have inclined them to say "different person." But this example identifies for us two conditions which are standardly fulfilled in the case in which we say "same person" and neither of which is standardly fulfilled in the case in which we say  "different person."  Of course,  if any expression were impossibly vague, this might  make it unfit for conceptual analysis; indeed, "impossibly vague" might mean "so vague as to be incapable of conceptual analysis." But this seems to me no reason to suppose that the expressions which, as a philosopher, I would wish to subject to conceptual analysis are, in general, impossibly vague. Moreover, one could only discover that they are impossibly vague by attempting to subject them to conceptual analysis and failing to reach any satisfactory result; it is odd, therefore, that the people who complain that ordinary language is too vague to be the subject of satisfactory conceptual analysis are usually also people who have never seriously tried to find satisfactory conceptual analyses, who have never philosophized in this way.  Objection C  "The sort of thing you say is an important part of philosophy is not worthy of the name 'philosophy. Philosophy is not just a matter of talking about words."  I cannot here discuss at length this particular objection, which is, I am sure, quite widely subscribed to; I can only indicate very briefly some lines which might be developed in reply.  (i) Why should "words" be mentioned with such contempt in this objection? Would the objector say to the grammarian, or to the phil-ologist, or to the linguist, in the same contemptuous tone, "You are merely concerned with talking about words"? I think not. Why then do "words" suddenly become contemptible if the philosopher talks about them?  (ii) There is a fairly close connection between some of the conceptual analyses proffered by contemporary philosophers and the dis-cussion which forms a central part of the writings of those who are generally recognized as great philosophers. Many of the great philosophers' questions can be interpreted as requests for a conceptual analysis (not necessarily in full with the greatest precision). No doubt the great philosophers themselves did not recognize the possibility of this kind of interpretation (how could they have?), but the link between contemporary discussion and their work is sufficiently close to provide some justification for the continued use of the term "philoso-phy." Moreover, it seems to me that many of the questions and puzzles raised by the great philosophers are capable of really clear and detailed and rigorous treatment after reinterpretation of this kind. If I have to choose between reinterpretation and continued mystifica-tion, I choose reinterpretation.  (ili) I carefully did not say that I thought that conceptual analysis of ordinary expressions was the whole of what I regard as the task of the philosopher. To begin with, I do not think it is necessary that, to be suitable for philosophical analysis, the use of an expression has to be "ordinary." The professional apparatus of the literary critic and the physicist (for example) may not consist of expressions in their ordinary use; nevertheless it may well be a philosopher's business to subject them to conceptual analysis, provided that they are expressions which their users can be in a position to use in particular cases, without being in a position to say (in general terms) everything there is to be said about how they are used. Furthermore, I think philosophers should be concerned with other questions besides questions of conceptual analysis. To mention only one example, a philosopher who has reached a decision about how an expression, or family of expressions, is used may well want (and often should want) to go on to ask such questions as "Why do we use these expressions this way, rather than some other way?" or "Could we have had a language in which there were no expressions which were used in this way" (e.g.  "Could we have had a language in which there were no singular terms?).  But I doubt if any of the other tasks which I would like to see the philosophers fulfill will be enough to satisty some people who raise this objection. They want philosophy to be grand, to yield one impor-tant, nonempirical information which will help one to solve either the world's problems or one's personal problems, or both. To them I feel inclined to reply in the end: "You are crying for the moon; philoso-phy has never really fulfilled this task, though it may sometimes have appeared to do so (and the practical consequences of its appearing to do so have not always been very agreeable). It is no more sensible to complain that philosophy is no longer capable of solving practical problems than it is to complain that the study of the stars no longer enables one to predict the course of world events." H. P. Grice.