Find counter arguments by entering NameVs… or …VsName.

Disputed term/author/ism | Author Vs Author |
Entry |
Reference |
---|---|---|---|

Quine, W.V.O. | Russell Vs Quine, W.V.O. | Prior I 39
Ramified type theory/rTT/Prior: first edition Principia Mathematica^{(1)}: here it does not say yet that quantification on non-nouns (non nominal) is illegitimate, or that they are only apparently not nominal. (Not on names?) But only that you have to treat them carefully. I 40
The ramified type theory was incorporated in the first edition.
(The "simple type theory" is, on the other hand, little more than a certain sensitivity to the syntax.)Predicate: makes a sentence out of a noun. E.g. "φ" is a verb that forms the phrase "φx". But it will not form a sentence when a verb is added to another verb. "φφ". Branch: comes into play when expressions form a sentence from a single name. Here we must distinguish whether quantified expressions of the same kind occur. E.g. "__ has all the characteristics of a great commander." Logical form: "For all φ if (for all x, if x is a great commander, then φx) then φ__". ΠφΠxCψxφx" (C: conditional, ψ: commander, Π: for all applies). Easier example: "__ has the one or the other property" Logical form: "For a φ, φ __" "Σφφ". (Σ: there is a) Order/Type: here one can say, although the predicate is of the same type, it is of a different order. Because this "φ" has an internal quantification of "φ's". Ramified type theory: not only different types, but also various "orders" should be represented by different symbols. That is, if we, for example, have introduced "F" for a predicative function on individuals" (i.e. as a one-digit predicate), we must not insert non-predicative functions for "f" in theorems. E.g. "If there are no facts about a particular individual ..." "If for all φ, not φx, then there is not this fact about x: that there are no facts about x that is, if it is true that there are no facts about x, then it cannot be true. I.e. if it is true that there are no facts about x, then it is wrong, that there is this fact. Symbolically: 1. CΠφNφxNψx. I 41
"If for all φ not φ, then not ψx" (whereby "ψ" can stand for any predicate). Therefore, by inserting "∏φφ" for "ψ":
2. CΠφNφxNΠφNφxTherefore, by inserting and reductio ad absurdum: CCpNpNp (what implies its own falsehood, is wrong) 3. CΠφNφx. The step of 1 to 2 is an impermissible substitution according to the ramified type theory. Sentence/ramified type theory/Prior: the same restriction must be made for phrases (i.e. "zero-digit predicates", propositions). Thus, the well-known old argument is prevented: E.g. if everything is wrong, then one of the wrong things would be this: that everything is wrong. Therefore, it may not be the case that everything is wrong. Logical form: 1. CΠpNpNq
by inserting:
2. CΠpNpNPpNpand so by CCpNpNp (reductio ad absurdum?) 3. NΠpNp, Ramified type theory: that is now blocked by the consideration that "ΠpNp" is no proposition of the "same order" as the "p" which exists in itself. And thus not of the same order as the "q" which follows from it by instantiation, so it cannot be used for "q" to go from 1 to 2. RussellVsQuine/Prior: here propositions and predicates of "higher order" are not entirely excluded, as with Quine. They are merely treated as of another "order". VsBranched type theory: there were problems with some basic mathematical forms that could not be formed anymore, and thus Russell and Whitehead introduce the reducibility axiom. By contrast, a simplified type theory was proposed in the 20s again. Type Theory/Ramsey: was one of the early advocates of a simplification. Wittgenstein/Tractatus/Ramsey: Thesis: universal quantification and existential quantification are both long conjunctions or disjunctions of individual sentences (singular statements). E.g. "For some p, p": Either grass is green or the sky is pink, or 2 + 2 = 4, etc.". (> Wessel: CNF, ANF, conjunctive and adjunctive Normal Form) Propositions/Wittgenstein/Ramsey: no matter of what "order" are always truth functions of indiviual sentences. Ramified Type TheoryVsRamsey/VsWittgenstein: such conjunctions and disjunctions would not only be infinitely long, but the ones of higher order would also need to contain themselves. E.g. "For some p.p" it must be written as a disjunction of which "for some p, p" is a part itself, which in turn would have to contain a part, ... etc. RamseyVsVs: the different levels that occur here, are only differences of character: not only between "for some p,p" and "for some φ, φ" but also between "p and p" and "p, or p", and even the simple "p" are only different characters. Therefore, the expressed proposition must not contain itself. 1. Whitehead, A.N. and Russel, B. (1910). Principia Mathematica. Cambridge: Cambridge University Press. |
Russell I B. Russell/A.N. Whitehead Principia Mathematica Frankfurt 1986 Russell II B. Russell The ABC of Relativity, London 1958, 1969 German Edition: Das ABC der Relativitätstheorie Frankfurt 1989 Russell IV B. Russell The Problems of Philosophy, Oxford 1912 German Edition: Probleme der Philosophie Frankfurt 1967 Russell VI B. Russell "The Philosophy of Logical Atomism", in: B. Russell, Logic and KNowledge, ed. R. Ch. Marsh, London 1956, pp. 200-202 German Edition: Die Philosophie des logischen Atomismus InEigennamen, U. Wolf (Hg) Frankfurt 1993 Russell VII B. Russell On the Nature of Truth and Falsehood, in: B. Russell, The Problems of Philosophy, Oxford 1912 - Dt. "Wahrheit und Falschheit" InWahrheitstheorien, G. Skirbekk (Hg) Frankfurt 1996 Pri I A. Prior Objects of thought Oxford 1971 Pri II Arthur N. Prior Papers on Time and Tense 2nd Edition Oxford 2003 |