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711 lines
41 KiB
Markdown
# Frank P. Ramsey — Review of Tractatus Logico-Philosophicus
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*Critical Notice, Mind*, New Series, Vol. 32, No. 128 (October 1923), pp. 465–478.
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Quelle: `resources/1923-ramsey zur Anhabdlung.pdf` (JSTOR-PDF).
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Konvertierung: pdftotext mit minimaler Aufräumung (Page-Numbers, Running Heads, JSTOR-Footer entfernt). Originalfehler im OCR (z. B. „THISis", „WIT'TGENSTEIN", „extraordinaryinterest", „macdeearlier") sind erhalten — bei präzisem Zitat mit dem Mind-Original abgleichen.
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---
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VI.-CRITICAL
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NOTICES.
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'Tractatus Logico-Philosophicus. BY LUDWIGWITTGENSTEIN, with
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an Introduction by BERTRAND RUSSELL.
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(International
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Library of Psychology, Philosophy and Scientific Method.)
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London: Kegan Paul, Trench, Trubner & Co. Ltd., 1922.
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Pp. 189. lOs. 6d.
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THISis a most important book containing original ideas on a large
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range of topics, forming a coherent system, which whether or not
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it be, as the author claims, in essentials the final solution of the
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problems dealt with, is of extraordinaryinterest and deserves the
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attention of all philosophers. And even if the system be altogether
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unsound the book contains a large numberof profound obiter dicta
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and criticisms of other theories. It is, however, very difficult to
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understand, in spite of the fact that it is printed with the German
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text and an English translation on opposite pages. Mr. Wittgenstein writes, not consecutive prose, but short propositions numbered
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so as to show the emphasis laid upon them in his exposition.
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This gives his work an attractive epigrammatic flavour, and perhaps makes it more accurate in detail, as each sentence must have
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received separate consideration; but it seems to have prevented
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him from giving adequate explanations of many of his technical
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terms and theories, perhaps because explanations require some
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,sacrificeof accuracy.
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This deficiency is partly made up by Mr. Russell's introduction;
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but it is possible that he is not an infallible guide to Mr. Wittgenstein's meaning. "In order to understand Mr. Wittgenstein's
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book, says Mr. Russell, "it is necessary to realise what is the
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problem with which he is concerned. In the part of his theory
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which deals with symbolism he is concerned with the conditions
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that would have to be fulfilled by a logically perfect language."
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This seems to be a very doubtful generalisation; there are, indeed,
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passages in which Mr. Wittgenstein is explicitly concerned with a
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logically perfect, and not with any language, e.g., the discussion of
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"logical syntax " in 3 325 if.; but in general he seems to maintain
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th?athis doctrines apply to Qrdinarylanguages in spite of the appearance of the contrary(see especially 4002 Sf.).' This is obviously
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an important point, for this wider application greatly increases the
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interest and diminishes the plausibility of any thesis suc,h as that
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which Mr. Russell declares to be perhaps the most fundamental in
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Mr. Wittgenstein's theory; that " In order that a certain sentence
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should assert a certain fact there must, however the language may
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466
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be constructed, be something in common between the structure of
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the sentence and the structure of the fact".
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This doctrine appears to depend on the difficult notions of a,
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"picture " and its " form of representation,"which I shall now try
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to explain and criticise.
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A picture is a fact, the fact that its elements are combinedwith
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one another in a definite way. These elements are co-ordinated
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with certain objects (the constituents of the fact of which the
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picture is a picture). These co-ordinations constitute the representing relation which makes the picture a picture. This representing relation "belongs to the picture" (2 1513); this I think
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means'that whenever we talk of a picture we 'have in mind some
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representing relation in virtue of which it is a picture. Under
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these circusnstances we say that the picture represents that the
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objects are so combined with another as are the elements of the
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picture, and this is the sense of the picture. And I think this must
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be taken to be the definition of "represents " and of " sense";
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that is to say, that when we say that a picture represents that
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certain objects are combined in a certain way, we mean merely
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that the elements of the picture are combined in that way, and are
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co-ordinated with the objects by the representing relation which
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belongs to the picture. (That this is a definition, follows, I think,
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from 5 542.)
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Light may be thrown on the "form of representation" by the
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following remarks macdeearlier in the book on the structureand
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form of facts. "The way in which objects hang together in the
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atomic fact is the structure of the atomic fact. The form is the
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possibility of the structure. The structureof the fact consists of
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the structures of the atomic facts" (2'032, 2-033, 2 034). The only
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point which I can see in the distinction between structureand form,
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is that the insertion of '' possibility" may include the case, in
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which the alleged fact whose form we are consideringis not a fact,
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whether or no
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so that we can talk of the form of the fact alb,abb
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is true, provided it is logically possible. It is to be regretted that,
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the above definitions do not make it clear whether two facts can
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ever have the same structure or the same form; it looks as if two
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atomic facts might well have the same structure,because objects
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hung together in the same way in each of them. But it seems
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from remarks later in the book that the structure of the fact is not
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merely the way in which the objects hang together but depends
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also on what objects they are, so that two differentfacts never have
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the same structure.
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A picture is a fact and as such has a structure and a form; we
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are, however, given the following new definitionsof its " structure"
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and its " form of tepresentation" in 2-15, 2-151. "That the elements of the picture are combined with one another in a definite
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way, represents that the things are so combined with one another.
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This connexion of the elements of the picture is called its structure,
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and the possibility of this structure is called the form of representa-
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LUDWIG
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Tractatus Logico-Philosophicus.
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tion of the picture. The form of representationis the possibility
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that, the things are so combined with one another as are the
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elements of the picture." This passage is puzzling; firstly, because
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we have here two differentdefinitions of the form of representation,
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and secondly, because it is not obvious how to interpret " this connexion" in the first of the two definitions; it may refer to the
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definite way in which the elements are combined, or to the whole
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of the preceding sentence, i.e., "this coinexion of the elements"
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may be that their combinationrepresents a similar combination of
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the things. On neither interpretationdoes the first definitionseem
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to coincide with the second. We can only hope to decide between
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these possible meanings of "form of representation" by considering
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the things which Mr. Wittgenstein says about it. Its chief property, which makes it of fundamental importance in his theory, is
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that asserted in 2-17: " What the picture must have in common
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with reality in order to be able to represent it after its mannerrightly or falsely-is its form of representation". Further, " what
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every picture, of whateverform, must have in common with reality
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in order to be able to represent it at all-rightly or falsely-is the
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logical form, that is, the form of reality. If the form of representation is the logical form, then the picture is called a logical picture.
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Every picture is also a logical picture. (On the other hand, for
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example, not every picture is spatial.)" (2-18, 2-181, 24182). It
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appears, then, that a picture may have several forms of representation, but one of these must be thelogical form; and that it is not
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asserted that the picture must have the same logical form as what,
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it pictures, but that all pictures must have the,logical form. This
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a,lso makes more plausible the deduction that the logical form of
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representationcannot be represented; for, that it was common ta
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one picture and reality, could afford no ground for supposing that
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it could not be representedin another picture.
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Now it is easy to seeI a sense in which a picture may have the
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spatial and must also have the logical form, namely, by taking the
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form to be the (possibility of the) way in which the elements of the
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picture are combined. (One of the interpretations of the first.
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definition given above.) This may be logical, as when the colour
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of a patch on a map represents the height above sea level of the
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corresponding patch of country; the elements of the picture are
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combined as predicate and subject and this represents that the
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corresponding things are also combined as predicate and subject.
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On the other hand the form may be spatial as when one dot being
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between two others represents that a certain town is between two
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others; but in this case we can also regard betweenness not as the
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way in which the dots are combined but as another element in the
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picture, which corresponds with itself. Then since betweenness
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and the dots are combined, not spatially, but as triple relation and
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its relata, that is logically, the form is logical. Here then we have
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something which may be spatial and must also be logical; but it
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does not follow that this is the form of representation,for the form
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468
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of representation may be some more complicated entity involving
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this and so derivatively spatial or logical. If. indeed, the above
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were what were meant by the form of representation,then in saying
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that a picture must have the logical form Mr. Wittgenstein would
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be saying no more than that it must be a fact; and in saying that we
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-cannotrepresent or speak about the logical form of representation,
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no more than that we crnnot talk about what makes a fact a fact,
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nor ultimately about facts at all, because every statement apparently
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about facts is really about their constituents. These things he
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certainly believes, but it seems to me unlikely that his complicated
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propositions about the form of representation amount to no more
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than this. Probably he is confused and does not use the term consistently; and if we revert to the second of the definitions given
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above, " The form of representationis the possibility that the things
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are so combined with one another as are the elements of the
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picture," we may discover another sense in which the picture has
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the form of representationin common with the pictured, namely,
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that the things with which its elements are co-ordinated by the
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representing relation are of such types that they can be combined
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in the same way as the elements of the picture; and so we arrive
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at the important principle that " The picture contains the possibility of the state of affairswhich it represents " (2 203). It seems
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to me, for reasons explained later, that the independent acceptance
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of this principle will justify almost all the non-mystical deductions
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which Mr. Wittgenstein makes from the necessity of something in
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common between the picture and the world, which cannot itself
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be represented; and that these deductions can so be given a firmer
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basis than is provided by the nature of this elusive entity, the form
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of representation, which is intrinsically impossible to discuss.
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In order to obtain any further comprehension of what Mr.
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Wittgenstein thinks a sentence must have in common with the
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fact which it asserts, or, indeed, of most of his book,it is necessary
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to understand his use of the word " proposition". This is, I think,
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made easier by the introduction of two words used by C. S. Peirce.
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A word, in the sense in which there are a dozen words ' the' on a
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page, he called a token; and these dozen tokens are all instances
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of one type, the word 'the'. Besides " word" there are other
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words which have this type-token ambiguity; thus a sensation, a
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thought, an emotion or an idea, may be either a type or a token.
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And in Mr. Wittgenstein's usage, in contrast, for instance, to Mr.
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Russell's in the Principles of Mathematics," proposition" also has
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type-token ambiguity.
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A propositionialsign is a sentence; but this statement must be
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qualified,for by " sentence " may be meant something of the same
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nature as the words of which it is composed. But a propositional
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sign differs essentially from a word because it is not an object or
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class of objects, but a fact, " the fact that its elements, the words,
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are combined in it in a definiteway " (3'14). Thus " propositional
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sign" has type-token ambiguity; the tokens (like those of any
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LIUDWIG WITTGENSTEIN,
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Tractatus Logico-Philosophicus.
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sign) are grouped into types by physical similarity (and by conventions associating certain noises with certain shapes) just as are
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the instancesof a word. But a propositionis a type whose instances.
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consist of all propositional sign tokens which have in common, not.
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a certain appearance,but a certain sense.
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As to the relation between a proposition and a thought Mr.
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Wittgenstein is rather obscure; but I think his meaning is that
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a thought is a type whose tokens have in common a certain sense,,
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and include the tokens of the correspondingproposition,but include
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also other non-verbal tokens; these, however, are not relevantly
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differentfrom the verbal ones, so that it is sufficient to consider the
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latter. He says "It is clear that 'A believes that p,' 'A thinks
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p, 'A says p,' are of the form 'p ' says p'" (5'542), and so explicitly reduces the question as to the analysis of judgment, to
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which Mr. Russell has at various times given different answers, to
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the question " What is it for a propositiontoken to have a certain
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sense?" This reduction seems to me an important advance, and
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as the question to which it leads is of fundamental importance,I
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propose to examine carefully what Mr. Wittgenstein says by way
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of answering it.
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First it may be remarkedthat if we can answer our question we.
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incidentally solve the problem of truth; or rather it is already evident that there is no such problem. For if a thought or proposition
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token " p " says p, then it is called true if p, and false if p. We
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can say that it is true if its sense agrees with reality, or if the possible state of affairs which it representsis the actual one, but these
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formulations only express the above definition in other words.
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According to Mr. Wittgeiistein a proposition token is a logical
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picture; and so its sense should be given by the definition of the
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sense of a picture; accordiriglythe sense of a proposition is that
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the things meant by its elements (the words) are combined with
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one another in the same way, as are the elements themselves, that
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is, logically. But it is evident that, to say the least, this definition
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is very incomplete; it can be applied literally only in one case,
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that of the completely analysed*-elementary proposition. (It
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may be explained that an elementary proposition is one which
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asserts the existence of an atomic fact, and that a proposition
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token is completelyanalysed if there is an element in it corresponding, to each object occurring in its sense.) Thus if " a " means a,
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"b " b, and "R," or more accurately the relation we establish between " a " and " b" by writing " aRb,"means R, then that " a "
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stands in this relation to " b" says that aRb,and this is its sense.
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But this simple scheme must evidently be modified,if, for example,
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one word is used for " having R to b " so that the propositionis not,
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completely analysed; or if we have to deal with a-morecomplicated
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propositionwhich contains logical constants such as " not " or " if,"
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which do not represent objects as names do. Mr. Wittgenstein
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does not make it quite clear how he proposes to deal with either of
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these difficulties. As regards the first, which he almost ignores, he
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470
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may reasonablyplead that it results from the enormous complication of colloquial language, which cannot be disentangled a priori;
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for in- a perfect language all propositions would be completely
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analysed except when we defined ,a sign to take the place of a string
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of simple signs; then, as he says, the defined sign would signify via
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the signs, by which it is defined. But the other difficulty must be
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faced, since we cannot be satisfied with a theory which deals only
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with elementarypropositions.
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The sense of propositions in general is explained by reference to
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,elemehtarypropositions. With regardto n elementarypropositions
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there are 2n possibilities of their truth and falsehood, which are
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called the truth-possibilities of the elementary propositions; similarly there are 2n possibilities of existence and non-existence of the
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'correspondingatomic facts. Mr. Wittgenstein says that any proposition is the expression of agreement and disagreement with the
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truth-possibilities of certain elementary propositions, and its sense
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is its agreementand disagreementwith the possibilities of existence
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-and non-existence of the corresponding atomic facts. (44, 42.)
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This is illustrated by the following symbolism for truth-functions.
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'T stands for true, F for false and we write the 4 possibilities for 2
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elementary propositions thus:p q
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T T
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F T
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T F
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F F
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Now by setting a T against a possibility for agreement and leaving
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;a blank for disagreement we can express, for example, p ) q, thus:
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p q
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T T T
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F T T
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T F
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F F T
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Or, adopting a conventionalorderfor the possibilities, (TT-T)(p, q).
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Evidently this notation does not in any way require p, q to be
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elementary propositions; and it can be extended to include propositions containing apparent variables. Thus p, q may be given
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LUDWIG
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Tractatus Logico-Philosophicus.
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not by enumeration but as all values of a propositional function,
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i.e., all propositions containing a certain expression (defined as
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"any part of a proposition which characterisesits sense" (3-31));
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and (--T)(s), where the solitary T expresses agreement only
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with the possibility that all the arguments are false, and Z is the
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set of values of fX, is what is written ordinarily as -: (Wx). fx.
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So every propositionis a truth-functionof elementary propositions,
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and many differently constructed propositional signs are the same
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proposition, because, expressing agreement and disagreement with
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the same truth-possibilities, they have the same sense and are the
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same truth-function of elementary propositions. Thus:
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q ) p:
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q ) p and - ( - p v ) are the same as p.
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This leads to an extremely simple theory of inference; if we call
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those truth-possibilities with which a proposition agrees, its truthgrounds, then q follows from p, if the truth-grounds of p are contained among those of q. In this case Mr, Wittgenstein also says
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that the sense of q is contained in that of p, that in asserting p we
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are incidentally asserting q. I think this statement is really a definition of containing as regards senses, and an extension of the
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meaning of assert partly in conformity with ordinary usage, which
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probably agrees as regardsp. q and p, or (x) . fx and fa but not
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otherwise.
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There are two extreme cases of great importance; if we express
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disagreement with all the truth-possibilitieswe get a contradiction,
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if agreement with them all, a tautology, which says nothing. The
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propositions of logic are tautologies and to have made clear this,
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their essential characteristic,is a remarkableachievement.
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We have now to consider whether the -above is an adequate
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account of what it is for a proposition token to have a certain
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sense; and it seems to me that it certainly is not. For it is really
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only an account of what senses there are, not of what propositional
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signs have what sense. It enables us to substitute for " 'p' says
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p," ' " p ' expressesagreement with these truth-possibilitiesanddisagreement with these others," but the latter formulation cannot be
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regarded as an ultimate analysis of the former, and it is not at all
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clear how its furtheranalysis proceeds. We have therefore to look
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elsewhere for the answer to our question. Towards this answer
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Mr. Wittgenstein does make a clear contribution; in 5-542, he says
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that in "'p ' says p " we have a co-ordination of facts by means of
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a co-ordinationof taeir objects. But this account is incomplete
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because the sense is not completely determinedby the objects which
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'occurin it; nor is the propositional sign completely constituted by
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the names which occur in it, for in it there may also be logical
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constants which are not co-ordinatedwith objects and complete the
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determinationof the sense in a way which is left obscure.
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If we had only to deal with one logical symbolism I do not think
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there would be any difficulty. For, apart from variation in the
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names used, there would be a rule giving all propositional signs
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472
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which, in that symbolism, had a certain sense, and we could complete the definition of "sense" by adding to it these rules. Thus
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" 'p ' says that
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aRb" would, supposing us to be dealing with
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the symbolism of FrincipiaMathematica, be analysed as follows:
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call anything meaning a, " a " and so on, and call "a" 'R" "b "
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q "; then 'p "iseither'' q ''or''
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"
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q "or' "q v q
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or any of the other symbols constructed accordingto a definite rule.
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(It may, of course, be doubted whether it is possible to formulate
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this rule as it seems to presuppose the whole of symbolic logic;
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but in any perfect notation it might be possible; for example in Mr.
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Wittgenstein's notation with T's and F's there would be no difficulty.) But it is obvious that this is not enough; it will not give
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an analysis of " A asserts p" but only of " A asserts p using such
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and such a logical notation". But we may well know that a
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Chinaman has a certain opinion without having an idea of the
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logical notation he uses' Also the evidently.-significant statement
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that German3use " nicht "for not becomes part of the definition
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of such words as " believe," "think" when used of Germans.
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It is very hard to see a way out of this difficulty; one may
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perhaps be found in Mr. Russell's suggestion in the Analysis of
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Mind (p. 250), that there may be special belief feelings occurring
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in disjunction and implication. Logical constants might then be
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significant as substitutes for these feelings, which would form the
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basis of a universal logical symbolism of human thought. But
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it looks as if Mr. Wittgenstein believes in another kind of solution,
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going back to his earlier statement that the sense of a picture is
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that the things are so combined with one another as are the elements of the picture. The natural interpretation of this in our
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present context is that we can only represent that a does not have
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a certain relation to b, by making " a " not have a certain relation
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to " b," or in general that only a negative fact can assert a negative
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fact, only an implicative fact an implicative fact and so on. This is
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absurdand evidently not what he means; but he does seem to hold
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that a proposition token resembles its sense somehow in this sort
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of way. Thus he says (5&512),"That which denies in I', p ' is not
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',' but that which all signs of this notation, which deny p, have
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in common. Hence the common rule according to which '- p,'
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'-_-- -p,"
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-Zp,v
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'p . -p,'
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etc. etc. (to infinity) are
|
||
-p,'
|
||
constructed. And this which is common to them all mirrors
|
||
denial." I cannot understand how it mirrorsdenial. It certainly
|
||
does not do so in the simple way in which the conjunction of two
|
||
propositions mirrors the conjunction of their senses. This difference between conjunctionand the other truth-functionscan be seen
|
||
in the fact that to believe p and q is to believe p and to believe q;
|
||
but to believe p or q is not the same as to believe p or to believe q,
|
||
nor to believe not p as not to believe p.
|
||
We must now turn to one of the most interesting of Mr.
|
||
Wittgenstein's theories, that there are certain things which cannot
|
||
be said but only shown, and these constitute the Mystical. The
|
||
|
||
|
||
LUDWIG
|
||
|
||
|
||
Tractatus Logico-Philosophicus.
|
||
|
||
|
||
reason why they cannot be said is that they have to do with the
|
||
logical form, which propositions have in common with reality.
|
||
What sort of things they are is explained in 4'122. "We can
|
||
speak in a certain sense of formal properties of objects and atomic
|
||
facts, or of properties of the structure of facts, and in the same
|
||
sense of formal relations and relations of structures. (Instead of
|
||
property of the structure I also say 'internal property'; instead
|
||
of relation of structures 'internal relation'. I introduce these
|
||
expressions in order to show the reason for the confusion, very
|
||
widespread among philosophers, between internal relations and
|
||
proper (external)relations.) The holding of such internal properties
|
||
and relations cannot, however, be asserted by propositions, but
|
||
shows itself in the propositions, which presept the atomic facts and
|
||
treat of the objects in question." As I have already said, it does
|
||
not seem to me that the nature of the logical form is sufficiently
|
||
clear to provide any cogent arguments in favour of such conclusions; and I think that a better approach to the treatment of
|
||
internal properties may be given by the following criterion: "A
|
||
property is internal if it is unthinkable that its object does not
|
||
possess it" (4123).
|
||
It is a principle of Mr. Wittgenstein's, and, if true, is a very
|
||
important discovery, that every genuine proposition asserts something possible, but not necessary. This follows from his account
|
||
of a proposition as the expression of agreement and disagreement,
|
||
with truth-possibilitiesof independent elementary propositions, so
|
||
that the only necessity is that of tautology, the only impossibility
|
||
that of contradiction. There is great difficultyin holding this; for
|
||
Mr. Wittgenstein admits that a point in the visual field cannot be
|
||
both red and blue; and, indeed, otherwise, since he\thinks induction
|
||
has no logical basis, we should have no reason for thinking that we
|
||
may not come upon a visual point which is both red and blue.
|
||
Hence he says that " This is both red and blue " is a contradiction.
|
||
This implies that the apparently simple concepts red, blue (supposing us to mean by those words absolutely specific shades) are
|
||
really complex and formally incompatible. He tries to show how
|
||
this may be, by analysing them in terms of vibrations. But even
|
||
supposing that the physicist thus provides an analysis of what we
|
||
mean by " red " Mr. Wittgenstein is only reducing the difficulty to
|
||
that of the necessary properties of space, time, and matter, or the
|
||
ether. He explicitly makes it depend on the impossibility of a
|
||
particle being in two places at the same time. These necessary
|
||
properties of space and time are hardly capable of a further reduction of this kind. For example, considering between in point
|
||
of time as regards my experiences; if B is between A and D and
|
||
C between B and D, then C must be between A and D; but it is
|
||
hard to see how this can be a formal tautology.
|
||
But not all apparently necessary truths can be supposed, or are
|
||
by Mr. Wittgenstein supposed, to be tautologies. There are also
|
||
the internal properties of which it is unthinkablethat their objects
|
||
|
||
|
||
474
|
||
|
||
|
||
do not possess them. Sentences apparently asserting such, properties of objects are held by Mr. Wittgenstein to be nonsense, but
|
||
to stand in some obscure relation to something inexpressible.
|
||
This last seems to be involved by his reason for thinking that they
|
||
are nonsense, which is that what they are meant to assert cannot
|
||
be asserted. But it seems to maepossible to give reasons why these
|
||
sentences are nonsense and a general account of their origin and
|
||
apparentsignificance, which have no mystical implications.
|
||
Sentences of this kind, which we call "pseudo-propositions,"
|
||
arise i-n various ways depending on our language. One source is
|
||
the grammaticalnecessity for such nouns as " object " and " thing "
|
||
which do not like ordinary common nouns correspond to propositional functions. Thus from "this is a red object" appears to
|
||
follow the pseudo-proposition "this is an object," which in the
|
||
symbolism of PrincipiaMathemcticacould not be written at all.
|
||
But the commonest and most important source is the substitution
|
||
of names or relative names for descriptions. (I use "relative
|
||
names" to include " p," the expression for a given sense p; in contrast to a description of that sense, such as " what I said.")
|
||
Usually this is legitimate; for, if we have a propositional schema
|
||
containing blanks, the significance of the schema when the blanks
|
||
are filled by descriptions presupposes, in general, its significance
|
||
when they are filled by the names of things answering to the
|
||
descriptions. Thus the analysis of " The 4)is red " is " There is
|
||
one and only one thing which is 4); and it is red" and the occurrence in this of " it is red" shows that the significance of our
|
||
proposition presupposes the significance of " a is red" where a is
|
||
of the type of the 4. But sometimes this is not the case because
|
||
the proposition containing the description must be analysed a little
|
||
differently. Thus " The 4 exists " is not " There is one and only
|
||
one thing which is 4); and it exists," but simply " There is one
|
||
and only one thing which is 4)"; so that its significance does not
|
||
presupposethat of " a exists," which is nonsense, for its truth could
|
||
be seen by mere inspection without comparison with' reality, as is
|
||
never the case with a genuine proposition. But partly because we
|
||
sometimes fail to distinguish " a exists," from " The object meant
|
||
by ' ' exists," and partly because "- exists " is always significant
|
||
when the blank is filled by a description,and we are not sufficiently
|
||
sensitive to the difference between descriptions and names; " a
|
||
exists " sometimes feels as if it were significant. Mr. Wittgenstein
|
||
gives in to this deceptive feeling so far as to hold that the existence of
|
||
the name " a " shows that a exists, but that this cannot be asserted;
|
||
it seems, however, to be a principal component in the mystical:
|
||
"Not howthe world is, is the mystical, but that it is" (6 44).
|
||
Our next example is provided by identity, of which Mr. Wittgenstein gives an importantdestructive criticism; " Russell's definition
|
||
of ' = ' won't do; because according to it one cannot say that two
|
||
objects have all their properties in common. (Even if this proposition is never true it is nevertheless significant)" (5 5302). And
|
||
|
||
|
||
LUDWIG
|
||
|
||
|
||
Tractatus Logico-Philosophicus.
|
||
|
||
|
||
"a = b " must be a pseudo-proposition since it is true or false
|
||
a prioriaccording as " a," " b " are names for the same, or different
|
||
things. If now we acdoptthe new convention that two different
|
||
signs in one proposition must have different meanings, we get
|
||
a new analysis of descriptions not involving identity. For f(7x) (+x)
|
||
instead of
|
||
(Rc) :Ox$), x=x c . fc
|
||
we have
|
||
(ax) xfx i:* -(Ex, Y).qtx .4fy.
|
||
And since (7x)(ox) = c is analysed as oc: (x, y) . Ox . Oy we
|
||
is only significant when one blank at least is
|
||
see that "- -"
|
||
filled by a description. Incidentally this rejection of identity may
|
||
have serious consequences in the theory of aggregates and cardinal
|
||
number; it is, for example, hardly plausible to say that two classes
|
||
are only of equal number when there is a one-one relation whose
|
||
domain is the one and converse domain the other, unless such relations can be constructed by means of identity.
|
||
Next I shall show how this account applies-tointernal properties
|
||
of the senses of propositions, or, if they are true propositions, the
|
||
corresponding facts. "p is about a" is an example; its significance might be thought to follow from that of " He said something
|
||
about a"; but if we reflect on the analysis of the latter proposition
|
||
we shall see that this is not the case; for it evidently reduces not
|
||
to " There is p, which he asserted and which is about a" but to
|
||
"1There is a function b such that he asserted Oa,"which. does not
|
||
involve -the pseudo-proposition " p is about a ". Similarly " p is
|
||
contradictory to q " might be thought to be involved in "He contradicted me "; but it is seen to be a pseudo-propositionwhen-we
|
||
analyse the latter as " There is p such that I asserted p, he
|
||
p ".
|
||
Of course this is not a complete analysis, but it is the first step and
|
||
sufficient for our present purpose and shows how "-is contradictory to-" is only significant when one blank at least is filled by
|
||
a description.
|
||
Other pseudo-propositions are those of mathematics, which,
|
||
according to Mr. Wittgenstein are equations obtained by writing
|
||
I = "between two expressions which can be substituted for one
|
||
another. I do not see how this account can be supposed to cover
|
||
the whole of mathematics, and it is evidently incomplete since
|
||
there are also inequalities, which are more difficult to explain. It
|
||
is, however, easy to see that " I have more than two fingers " does
|
||
not presuppose the significance of " 10> 2 "; for, remembering
|
||
that different signs must have different meanings, it is simply
|
||
"(ax, y, z): x, y, z are fingers of mine ".
|
||
Just as the explanation of some apparently necessary truths as
|
||
tautologies met with difficulty in the field of colour, so does the
|
||
explanation of the remainder as pseudo-propositions. " This blue
|
||
colour and that," says Mr. Wittgenstein, " stand in the internal relation of brighter and darker eo ipso. It is unthinkable that -these
|
||
two objects should not stand in this relation" (4123). Accordingly
|
||
a sentence apparently asserting that one named colour is brighter
|
||
|
||
|
||
476
|
||
|
||
|
||
than another named colour must be a pseudo-proposition; but it
|
||
is hard to see how this can be reconciled with the indubitable significance of a sentence asserting that a described colour is brighter
|
||
than another, such as " My cushion at home is brighter than my
|
||
carpet ". But in this case the difficulty could be completely removed by the supposition that the physicist is really analysing the
|
||
meaning of " red; " for his analysis of a colour comes eventually to
|
||
a number, such as the length of a wave or what not, and the difficulty is reduced to that of reconciling the non-significance of an
|
||
inequality between two given numbers with the significance of an
|
||
inequality between two described numbers, which is evidently
|
||
somehow possible on the lines suggested for " I have more than
|
||
two fingers" above.
|
||
Let us now pass to Mr. Wittgenstein's account of philosophy.
|
||
"The object of philosophy," he says, " is the logical clarificationof
|
||
thoughts. Philosophy is not a theory but an activity. A philosophical work consists essentially of elucidations. The result of
|
||
philosophy is not a number of philosophical propositions but to
|
||
make propositions clear. Philosophy should make clear and delimit sharply the thoughts which otherwise are, as it were, opaque
|
||
and blurred" (4.112). It seems to me that we cannot be satisfied
|
||
with this account without some further explanation of " clarity,"
|
||
and I shall try to give an explanation in harmony with Mr.
|
||
Wittgenstein's system. I think that a written sentence is " clear "
|
||
in so far as it has visible properties correlatedwith or " showing"
|
||
the internal properties of its sense. Accordingto Mr. Wittgenstein
|
||
the latter always show themselves in internal properties of the
|
||
proposition; but owing to the type-token ambiguity of " proposition" it is not immediately clear what this means. Properties
|
||
of a proposition must, I think, mean properties of all its tokens;
|
||
but, the internal properties of a proposition are those properties of
|
||
the tokens which are, so to speak, internal not to the tokens but to
|
||
the type; that is, those which, one of the tokens must have if it is
|
||
to be a token of that type, not those which it is unthinkable that it
|
||
should not have anyhow. We must remember that there is no
|
||
necessity for a sentence to have the sense it does in fact have; so
|
||
that if a sentence says fa, it is not an internal property of the
|
||
sentence that there is something in it somehow connected with a;
|
||
but this is an internal property of the proposition, because the
|
||
sentence could not otherwise belong to that proposition type, i.e.,
|
||
have that sense. So we see that the internal properties of a
|
||
proposition which show those of its sense are not, in general,
|
||
visible ones, but complicated ones involving the notion of meaning.
|
||
But in a perfect language in which each thing had its own one
|
||
name, that in the sense of a sentence a certain object occurred,
|
||
would be also shown visibly by the occurrence in the sentence of
|
||
the name of that object; and this might be expected to happen
|
||
with regard to all internal properties of senses; that one sense, for
|
||
example, is contained in another (i.e., one proposition follows from
|
||
|
||
|
||
LUDWIG WITTGENSTEIN,
|
||
|
||
Tractatus Logico-Philosophicus.
|
||
|
||
|
||
another) might always appear visibly in the sentences expressing
|
||
them. (This is nearly achieved in Mr. Wittgenstein's T notation.)
|
||
Thus in a perfect language all sentences or thoughts would be perfectly clear. To give a general definition of "clear " we must replace " visible property of the sentence " by "internal property of
|
||
the propositionalsign," which we interpretanalogouslyto " internal
|
||
propertyof the proposition" as a property which a token must have
|
||
if it is to be that sign, which, if the token is written, is the same
|
||
as a visible property. We say then that a propositional sign is
|
||
clear in so far as the internal propertiesof its sense are shown not
|
||
only by internal properties of the proposition but also by internal
|
||
propertiesof the propositionalslgn.
|
||
(It may perhaps be confusion between the internal properties of
|
||
the proposition and those of the propositionalsign which gives rise
|
||
to the idea that Mr. Wittgenstein's doctrines are, in general, only
|
||
asserted of a perfect language.)
|
||
We can easily interpret this idea of philosophy in terms of the
|
||
non-mystical account of internal properties given above. First we
|
||
notice and explain the fact that we often apparently do or do not
|
||
recognise that something has an internal property, although this is
|
||
a pseudo-propositionand so cannot be recognised. What we really
|
||
recognise is that "the object or sense meant or asserted by the
|
||
words before us has this property,"which is significant because we
|
||
have substituted a description for a name. Thus as the result of
|
||
logical proof we recognise, not that p is a tautology which is a
|
||
pseudo-proposition,but that "p" says nothing. To make propositions clear is to facilitate the recognition of their logical
|
||
properties by expressing them in languagesuch that these properties
|
||
are associated with visible properties of the sentence.
|
||
But I think this activity will result in philosophical propositions
|
||
whenever we discover anything new about the logical form of the
|
||
senses of any interesting body of sentences, such as those expressing the facts of perception and thought. We must agree with Mr.
|
||
Wittgenstein that " p is of such and such a form " is nonsense, but
|
||
'9' p' has a sense of such and such a form " may nevertheless not
|
||
be nonsense. Whether it is or not depends on the analysis of
|
||
"' p' is significant,"which seems to me probablya disjunctive proposition, whose alternatives arise partly from the differentpossible
|
||
forms 'of the sense of " p ". If this is so, we can by excluding some
|
||
of these alternatives make a proposition as to the form of the sense
|
||
|
||
of "p ". And this in certaincases, such as when " p " is " He thinks
|
||
q" or "He sees a," could be appropriatelycalled a philosophical
|
||
proposition. Nor would this be incompatible with Mr. Wittgenstein's more moderate assertion that "IMost propositions and
|
||
questions, that have been written about philosophical matters, are
|
||
not false but senseless. We cannot therefore answer questions of
|
||
this sort at all but only state their senselessness. Most questions
|
||
and propositionsof the philosophers result from the fact that we
|
||
do not understand the logic of our language" (4 003).
|
||
|
||
|
||
478
|
||
|
||
|
||
Lastly I wish to touch on Mr. Wittgenstein's general view of the
|
||
world. " The world," he says, " is the totality of facts not of things "
|
||
(1-1) and " it is clear that however different from the real one an
|
||
imagined world may he, it must have something-a form-in
|
||
common with the real world. This fixed form consists of the
|
||
objects" (2-022,2 023). It is an unusual view that any imaginable
|
||
world must contain all the objects of the real one; but it seems to
|
||
follow from his principles, for if " a exists " is nonsense, we cannot
|
||
imaginethat it does not exist, but only that it does or does not have
|
||
some property.
|
||
Mr. Russell in his introduction finds an acute difficulty in the
|
||
fact that (x) . ox involves the totality of values of 4x and so, apparently, that of the values of x, which according to Mr. Wittgenstein cannot be spoken of; for it is one of his fundamental theses
|
||
" that it is impossible to say anything about the world as a whole,
|
||
and that whatever can be said has to be about bounded portions of
|
||
the world". It seems doubtful, however, whether this is a fair
|
||
expression of Mr. Wittgenstein's view; for one thing, it suggests
|
||
that it is impossible to say (x) . ox, but only perhaps " All S are
|
||
P," taken as asserting nothing about the non-S's, which he cer-
|
||
|
||
tainly does not maintain. It may, then, be interesting to consider
|
||
what he says which gives plausibility to Mr. Russell's interpretation.
|
||
He does undoubtedly deny that we can speak of the number of all
|
||
objects (4-1272). -But this is not because all objects form an illegitimate totality, but because "object" is a pseudo-concept expressed not by a function but by the variable x. (Incidentally I
|
||
do not see why the number of all objects should not be defined as
|
||
the sum of the number of things having any specified propertyand
|
||
the number of things not having that property.) Also he says that
|
||
"The feeling of the world as a limited whole is the mystical
|
||
feeling" (6A45). But I do not think we can follow Mr. Russell in
|
||
deducing from this that the totality of values of x is mystical, if
|
||
only because "the world is the totality of facts not of things"
|
||
(141). And I think that " limited " gives the key to the sentence
|
||
quoted above. The mystical feeling is the feeling that the world
|
||
is not everything, that there is something outside it, its " sense"
|
||
or Itmeaning '.
|
||
It must not be thought that the topics I have discussed nearly
|
||
exhaust the interest of the book; Mr. Wittgenstein makes remarks,
|
||
always interesting, sometimes extremely penetrating, on many
|
||
other subjects, such as the. Theory of Types, Ancestral-Relations,
|
||
Probability,the Philosophy of Physics and Ethics.
|
||
F. P. RAMSEY.
|
||
|
||
|
||
|