「定義論争意味ねえ」論

捜し物の１つをたまたま某先生がTwitterで訳書の方を抜粋してたので，原書で確認したYO:

And because society will never be perfect, to raise questions like 'What is the ideal form of society?' is academic. Indeed, Popper condemns 'what is?' questions generally: 'What is gravity?' and 'What is life?' are as irrelevant to making progress in science (see pp. 34 and 49) as 'what is freedom?' and 'What is justice?' are to making progress in politics. Equally to be condemned are 'What is?' questions disguised by being at one remove – for instance ‘Is Britain really a democracy?' which leads straight to 'What do you mean by democracy?' or 'What is democracy?'. Their quasimagical attempt to capture the essence of reality in a definition has led Popper to brand the use of such questions as 'essentialism'. In politics the essentialist approach leads almost naturally to Utopianism and doctrinal conflict. Genuinely important questions are more like 'What should we do in these circumstances? What are your proposals?'. To them the answers can be fruitfully discussed and criticized; and then, if they stand up to that, tried out. Nothing that is not a proposal can ever be put into practice. So what matters in politics, as in science, is not the analysis of concepts but the tests of experience. (Bryan Meggee, Popper (3rd edition). Fontana Press, 1973/1985, pp.106-7) [Amazon]

訳書は持ち合わせてないので，拙訳を当てておく：

社会が完璧になることなどないのだから，「理想の社会形態とはなにか？」のような問いを立てるのは学者論議というものだ．それどころか，「とは何か？」式の問い全般をポパーはこき下ろしている：「重力とはなにか？」「生命とはなにか？」といった問いは科学を進歩させるのに関係がないし（pp.34 & 49 参照），「自由とは何か？」「正義とは何か？」といった問いは政治を進歩させるのに関係ない．同じくこきおろされているのが，偽装してこそいるが一皮むけばそれとわかる「とは何か」式の問いだ――たとえば「イギリスは本当に民主国家なのか？」という問いは，すぐに「きみが言う民主国家とはなにか？」「民主国家とは何か？」といった問いにつながる．現実の本質を定義でつかまえようとするこうした魔術めいた試みがなされるのを見て，ポパーはこうした問いの使用を「本質主義」と名付けた．政治の世界では，本質主義的なやり方はほぼ自然にユートピア主義と教義論争にいたる．まぎれもなく重要な問いは，こういうものではなく「この状況ですべきことはなにか？」「きみにはどんな提案がある？」といった問いだ．こうした問いなら，実のある議論と批判ができる．そして，議論と批判に耐えたものを試せばいい．提案ではないものは実地に試せない．科学と同じく政治の世界でも，重要なのは概念の分析ではなくて経験による検証の方だ．

上の引用で参照されてる p.34 と pp.49-50 にはこうある：

At every level, then, our knowledge can consist only of our theories. And our theories are the products of our minds. Even the concepts with which we think are not, as empiricists from Locke and Hume to the present day have believed, 'given to us from outside by objective regularities in our environment, but are developed by us in response to our own problems, interests and points of view: like our knowledge they too are made, not found. But of a concept it cannot be asked, as it can of a theory, whether it is true or false; and the asking of what is?' questions about concepts ('What is life?' ... What is mind?') leads to sterile analysis and verbalism (more of this in the next chapter). So we should eschew the elucidation of concepts for the testing of theories. (ibid., p.34)

Not only was Popper not putting forward a criterion of meaning: he has always held that to do so is a major philosophical error. He also believes that habitual discussion of the meanings of words is not only boring but harmful. The notion that we must define our terms before we can have a useful discussion is, he holds, demonstrably incoherent, for every time one defines a term one has to introduce new terms in the definition (otherwise the definition is circular) and one is then required to define the new terms. So we can never get to the discussion at all, because we can never complete the necessary preliminaries. Discussion, then, has to make use of undefined terms. Similarly the notion that precise knowledge requires precise definition is demonstrably wrong. Physicists are not in the habit of debating the meaning of terms like 'energy', light, and all the other concepts they habitually employ. Precise analysis and definition of such terms would present inexhaustible difficulties, and physicists leave them for the most part undefined. Yet the most accurate and extensive knowledge we have is in the physical sciences. Another point to be made about good definitions in science is that they are, as Popper puts it, properly to be read from right to left and not from left to right. The sentence 'A di-neutron is an unstable system comprising two neutrons' is the scientists' answer to the question What shall we call an unstable system comprising two neutrons?', not an answer to the question 'What is a dineutron ?' The word 'di-neutron' is a handy substitute for a long description, that is all: no information about physics is to be gained from analysing it. Physics would go on exactly the same without it: only communication would have been made a little more cumbersome. The view that the precision of science and of scientific language depends upon the precision of its terms is certainly very plausible, but it is none the less, I believe, a mere prejudice. The precision of a language depends, rather, just upon the fact that it takes care not to burden its terms with the task of being precise. A term like "sand-dune" or "wind" is certainly very vague. (How many inches high must a little sand-hill be in order to be called "sand-dune"? How quickly must the air move in order to be called "wind"?) However, for many of the geologist's purposes, these terms are quite sufficiently precise; and for other purposes, when a higher degree of differentiation is needed, he can always say "dunes between 4 and 30 feet high" or "wind of a velocity of between 20 and 40 miles an hour". And the position in the more exact sciences is analogous. In physical measurements, for instance, we always take care to consider the range within which there may be an error; and precision does not consist in trying to reduce this range to nothing, or in pretending that there is no such range, but rather in its explicit recognition."　(ibid., pp.49-50)