Disputed term/author/ism | Author Vs Author |
Entry |
Reference |
---|---|---|---|
Frege, G. | Prior Vs Frege, G. | I 50 Truth Value/PriorVsFrege: Problem: the term "truth value": was invented by him, but originally for mathematical contexts. Value: to be "greater than 0" is, strictly speaking, not the "value" of a function for a given argument. The value for this argument is not a property of a number (e.g. to be > 0). But a number! The value of a function is different for different arguments and is not the whole collection (Frege: value curve!) of values. Frege: sentences designate objects that are called truth and falsity. Namely in the same way as number names (numerals) and formulas contain the number names, designate numerals. Which number is designated by a given function expression depends on which number is designated by the expression argument, and by nothing else. Prior: if the analogy is to last, then whether truth or falsity is designated must depend on what is designated by the argument sentence ((s) the cited belief), and on nothing else ((s) i.e. it would always have to be believed that grass is green, simply because it is true - absurd.) Prior: E.g. that it is not the case that the grass is pink, just like 2-1 > 0 (and also other things, such as is its own square!), according to Frege this is not simply supposed to be "true", but "the true thing". That is to correspond to the fact that 2-1 is not only "> 0", but the number 1! I 51 And that it is not the case that the grass is pink is "the true thing" (truth), precisely because the grass is pink is "the false thing". Analogy: "the false thing" as in: (1 + 1) 1 is the number 1, precisely because 1 + 1 is the number 2, because that grass is pink is the wrong thing just like (3-1) 1 is the number 1, because 3-1 is the number 2. There are no different truths. PriorVsFrege: all this follows if Frege's analogy is true. But of course it is false. Truth and falsity are more like properties of what sentences designate. That is what Frege wanted to avoid. But we have said above that sentences denote nothing. Propositions/Prior: only have Pickwickian meaning! (WittgensteinVsBroad: (Wittgenstein II 94): There is not one "special" meaning apart from the "ordinary" meaning) Prior: but we know enough to see that this is harmless. We know what it means, that 1 is > 0, namely, since for each φ and each ψ if exactly one thing φs and no thing ψs, then more things are φ-ing than are ψ-ing. Def "more than". I 51/52 Function/Sentence/Prior: it is a function of the sense of "grass is pink" to be expressed by the sentence "X believes that grass is pink". Distinction without Difference/Prior: but that makes no difference! That this is not the case, is exactly what makes the belief false. There is no thing that is designated with "grass is pink". (VsFrege: i.e. also not "the wrong thing", but that is not what Frege meant, either). Truth functions and belief functions are functions of the same argument!(?). Def Proposition/(Thoughts?)/Church: have the property of "being the concept of truth or falsity." Thoughts/PriorVsFrege: among the functions of his thought we have those that are related to each other, just as the functions of the true and false are related to each other and we can omit the latter as superfluous. But the extensionalists have made the stone that we have jettisoned their milestone! PriorVsFrege: Conclusion: sentences do not designate anything, not even "the true thing" or "the false thing". Extensionalism/Prior: Thesis: sentences have truth values as their "extension". I 53 PriorVs: they have that as little as predicates have classes as their extension. For truth values and classes are both logical constructions and very similar ones at that! And not "objects". (PriorVsPlatonism, VsExistence of classes and truth values as objects). Names/Variables/Prior: there is a doctrine among American logicians that every bound variable stands for a name. PriorVs: that is too eccentric a criterion for names. Ontology/Individual/Prior: in reality, combines the principle that only individuals are real with the view that the only way for us to grasp individuals linguistically is to treat them as applications of nouns. And that their application is unique is something that can be expressed within the system, and not with Russell's logical proper names (this, or descriptions) I 166 but with Lesniewski's functor "e" or "This __ is a __". Description/ Frege: for him, the expression "the such and such" itself an individual name (individual name, singular name). PriorVsFrege: there are no individual names! Instead, the expression occurs as part of a longer functor that carries out the individuation. This/Oxford: many there are not happy about Russell's logical proper names. |
Pri I A. Prior Objects of thought Oxford 1971 Pri II Arthur N. Prior Papers on Time and Tense 2nd Edition Oxford 2003 |
Platonism | Prior Vs Platonism | I 52 Extensionalism/Prior: Thesis: sentences have truth values as their "extension". I 53 PriorVs: they have that as little as predicates have classes as an extension. For truth value and classes are both logical constructions, and very similar ones at that! And no "objects". (PriorVsPlatonism, VsExistence of classes and truth values as objects). |
A. Prior I Prior Gedankenobjekte Oxford 1971 Propositionen und Tatsachen |