Review of Acquaintance and Description Again

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Review: [Untitled] Reviewed Work(s): Acquaintance and Description Again. by Wilfrid Sellars Alonzo Church The Journal of Symbolic Logic, Vol. 15, No. 3. (Sep., 1950), p. 222. Stable URL: http://links.jstor.org/sici?sici=0022-4812%28195009%2915%3A3%3C222%3AAADA%3E2.0.CO%3B2-H The Journal of Symbolic Logic is currently published by Association for Symbolic Logic.

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REVIEWS

extent that the same term ought not t o be used. I t is said that Copi's claim may amount t o no more than a restatement in misleading philosphical language of one of the Godel incompleteness theorems. There is also an interesting discussion of the results of Leon Henkin's dissertationespecially of the point that the Godel undecidable sentence in a language L, though i t be true when L is interpreted as referring to a standard model, may nevertheless be false for a suitably chosen non-standard model. This is used t o render plausible the author's concluding suggestion that the undecidable sentence should perhaps be regarded as an example of a formula which, though well-formed, is nevertheless without meaning. But i t must be pointed out t h a t this is the same suggestion which Copi, also on plausible grounds, rejects as "a very curious view indeed." ALONZO C HURCH WILFRIDSELLARS.Acquaintance and description again. Ibid., vol. 46 (1949), pp. 496504. Since Russell's well-known analysis reduces a sentence containing (or apparently containing) a description t o one t h a t contains a n existential quantifier instead, a discussion of Russell's doctrine of descriptions leads up t o the question whether a n existential sentence (3x)Fx can be regarded as "definitionally equivalent" to the disjunction Fxl v Fxz v Fx, v . , where XI, xt, xo, . . . i s a (supposed) complete list of the names of "basic particulars" or individuals. The author's own answer to this question, "I want to suggest that in the logical frame of reference, where i t obviously belongs, this is a perfectly legitmate statement," is given very briefly and is not meant t o be final. In the reviewer's opinion, the existential sentence and the corresponding disjunction must be regarded as differing in sense or intensional meaning-even if the domain of inALONZO CHURCH dividuals should chance t o be finite. Compare 4561, pp. 316-317.

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C. H. LANGFORD.The nature of formal analysis. Mind,n.s. vol. 58 (1949), pp. 210-214. Langford holds t h a t a formal analysis relates neither expressions alone nor concepts alone, but rather usages. A usage consists of a n expression together with the concept i t expresses; and two usages are synonymous if and only if their conceptual components are the same. A partial usage consists of a symbolically relevant part of a n expression together with the concept expressed by that part. I n a formal analysis, (1) the analysandum and the analysans are synonymous usages, (2) every partial usage of the analysandum is synonymous with some partial usage of the analysans, and (3) some partial usage of the analysans is synonymous with no partial usage of the analysandum. 'Symbolically relevant' is not explained, and one wonders how i t could be so interpreted that (2) will be satisfied both by the examples of analysis t h a t Langford gives and by such examples as 'A red herring is a subject introduced t o divert attention.' This, however, is a minor matter. The point that an analysans must be somehow more articulate than its analysandum is obviously correct; but i t does not, as Langford supposes, touch the central problem involved in the "paradox of analysis." For virtually the same problem-which in the reviewer's opinion results from untenable notions concerning meaning-arises with respect t o equations of equally articulate expressions, e.g. 'a lorry is a truck.' NELSONGOODMAN

M. COPI. Lewis Carroll's barber shop paradm. Ibid., ARTHURW. BURKGand IRVING n.s. vol. 59 (1950), pp. 219-222. The authors point out that the 'paradox' in question is not a true logical paradox, but merely a difficulty arising from the ambiguity of the English phrase 'if . .'.then . . .'. They . then . . .' of Carroll t o be causal propose t o avoid the difficulty by interpreting the 'if implication. With such an interpretation, Carroll's argument collapses because of the fact that 'exportation' is not a valid form of inference for causal implication: i.e., introducing the symbol 'c' t o denote causal implication, and letting 'A,' 'B,' and 'C' stand for arbitrary statements, we cannot conclude, t h a t A c (B c C) is true, from the mere fact that (AB) c C is true.

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