Combining Texts

All the ideas for 'fragments/reports', 'The Theory of Logical Types' and 'Pragmatism in Retrospect'

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9 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Even pointing a finger should only be done for a reason [Epictetus]
     Full Idea: Philosophy says it is not right even to stretch out a finger without some reason.
     From: Epictetus (fragments/reports [c.57], 15)
     A reaction: The key point here is that philosophy concerns action, an idea on which Epictetus is very keen. He rather despise theory. This idea perfectly sums up the concept of the wholly rational life (which no rational person would actually want to live!).
3. Truth / E. Pragmatic Truth / 1. Pragmatic Truth
Peirce's theory offers anti-realist verificationism, but surely how things are is independent of us? [Horsten on Peirce]
     Full Idea: Peirce's anti-realist theory of a truth is a verificationist theory. Truth is judged to be an epistemic notion. But the way things are is independent of the evidence we may be able to obtain for or against a judgement.
     From: comment on Charles Sanders Peirce (Pragmatism in Retrospect [1906]) by Leon Horsten - The Tarskian Turn 02.1
     A reaction: This criticism doesn't quite capture the point that Peirce's theory is that truth is an ideal, not the set of opinions that miserable little humans eventually settle for when they get bored. Truth is an aspect of rationality, perhaps.
Independent truth (if there is any) is the ultimate result of sufficient enquiry [Peirce]
     Full Idea: I hold that truth's independence of individual opinions is due (so far as there is any 'truth') to its being the predestined result to which sufficient enquiry would ultimately lead.
     From: Charles Sanders Peirce (Pragmatism in Retrospect [1906], p.288)
5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic
'Propositional functions' are ambiguous until the variable is given a value [Russell]
     Full Idea: By a 'propositional function' I mean something which contains a variable x, and expresses a proposition as soon as a value is assigned to x. That is to say, it differs from a proposition solely by the fact that it is ambiguous.
     From: Bertrand Russell (The Theory of Logical Types [1910], p.216)
     A reaction: This is Frege's notion of a 'concept', as an assertion of a predicate which still lacks a subject.
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
'All judgements made by Epimenedes are true' needs the judgements to be of the same type [Russell]
     Full Idea: Such a proposition as 'all the judgements made by Epimenedes are true' will only be prima facie capable of truth if all his judgements are of the same order.
     From: Bertrand Russell (The Theory of Logical Types [1910], p.227)
     A reaction: This is an attempt to use his theory of types to solve the Liar. Tarski's invocation of a meta-language is clearly in the same territory.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Type theory cannot identify features across levels (because such predicates break the rules) [Morris,M on Russell]
     Full Idea: Russell's theory of types meant that features common to different levels of the hierarchy became uncapturable (since any attempt to capture them would involve a predicate which disobeyed the hierarchy restrictions).
     From: comment on Bertrand Russell (The Theory of Logical Types [1910]) by Michael Morris - Guidebook to Wittgenstein's Tractatus 2H
     A reaction: I'm not clear whether this is the main reason why type theory was abandoned. Ramsey was an important critic.
Classes are defined by propositional functions, and functions are typed, with an axiom of reducibility [Russell, by Lackey]
     Full Idea: In Russell's mature 1910 theory of types classes are defined in terms of propositional functions, and functions themselves are regimented by a ramified theory of types mitigated by the axiom of reducibility.
     From: report of Bertrand Russell (The Theory of Logical Types [1910]) by Douglas Lackey - Intros to Russell's 'Essays in Analysis' p.133
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
A one-variable function is only 'predicative' if it is one order above its arguments [Russell]
     Full Idea: We will define a function of one variable as 'predicative' when it is of the next order above that of its arguments, i.e. of the lowest order compatible with its having an argument.
     From: Bertrand Russell (The Theory of Logical Types [1910], p.237)
     A reaction: 'Predicative' just means it produces a set. This is Russell's strict restriction on which functions are predicative.
12. Knowledge Sources / D. Empiricism / 3. Pragmatism
Pragmatism is a way of establishing meanings, not a theory of metaphysics or a set of truths [Peirce]
     Full Idea: Pragmatism is no doctrine of metaphysics, no attempt to determine the truth of things. It is merely a method of ascertaining the meanings of hard words and of abstract concepts.
     From: Charles Sanders Peirce (Pragmatism in Retrospect [1906], p.271)
     A reaction: Suddenly I recognise a prominent strand of modern philosophy of language (especially in America) for what it is.