Combining Philosophers

Ideas for Roger Penrose, Michael Dummett and Fred Dretske

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12 ideas

18. Thought / A. Modes of Thought / 1. Thought
A theory of thought will include propositional attitudes as well as propositions [Dummett]
     Full Idea: A comprehensive theory of thought will include such things as judgement and belief, as well as the mere grasp of propositions.
     From: Michael Dummett (Thought and Reality [1997], 4)
     A reaction: This seems to make any theory of thought a neat two-stage operation. Beware of neatness. While propositions might be explained using concepts, syntax and truth, the second stage looks faintly daunting. See Idea 2209, for example.
The theories of meaning and understanding are the only routes to an account of thought [Dummett]
     Full Idea: For the linguistic philosopher, the theory of meaning, and the theory of understanding that is built upon it, form the only route to a philosophical account of thought.
     From: Michael Dummett (Thought and Reality [1997], 4)
     A reaction: I am of the party that thinks thought is prior to language (esp. because of animals), but Dummett's idea does not deny this. He may well be right that this is the 'only route'. We can only hope to give an account of human thought.
18. Thought / D. Concepts / 3. Ontology of Concepts / c. Fregean concepts
Concepts only have a 'functional character', because they map to truth values, not objects [Dummett, by Davidson]
     Full Idea: Real functions map objects onto objects, but concepts map objects onto truth value, ...so Dummett says that concepts are not functions, but that they have a 'functional character'.
     From: report of Michael Dummett (Frege Philosophy of Language (2nd ed) [1973]) by Donald Davidson - Truth and Predication 6
18. Thought / D. Concepts / 4. Structure of Concepts / i. Conceptual priority
Maybe a concept is 'prior' to another if it can be defined without the second concept [Dummett]
     Full Idea: One powerful argument for a thesis that one notion is conceptually prior to another is the possibility of defining the first without reference to the second.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12)
     A reaction: You'd better check whether you can't also define the second without reference to the first before you rank their priority. And maybe 'conceptual priority' is conceptually prior to 'definition' (i.e. definition needs a knowledge of priority). Help!
An argument for conceptual priority is greater simplicity in explanation [Dummett]
     Full Idea: An argument for conceptual priority is greater simplicity in explanation.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12)
     A reaction: One might still have to decide priority between two equally simple (or complex) concepts. I begin to wonder whether 'priority' has any other than an instrumental meaning (according to which direction you wish to travel - is London before Edinburgh?).
18. Thought / E. Abstraction / 1. Abstract Thought
Abstract terms are acceptable as long as we know how they function linguistically [Dummett]
     Full Idea: To recognise abstract terms as perfectly proper items of a vocabulary depends upon allowing that all that is necessary for the lawful introduction of a range of expressions into the language is a coherent account of how they are to function in sentences.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.16)
     A reaction: Why can't the 'coherent account' of the sentences include the fact that there must be something there for the terms to refer to? How else are we to eliminate nonsense words which obey good syntactical rules? Cf. Idea 9872.
You can't infer a dog's abstract concepts from its behaviour [Dummett]
     Full Idea: One could train a dog to bark only when a bell rang and a light shone without presupposing that it possessed the concept of conjunction.
     From: Michael Dummett (Truth [1959], p.235)
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
Since abstract objects cannot be picked out, we must rely on identity statements [Dummett]
     Full Idea: Since we cannot pick an abstract object out from its surrounding, all that we need to master is the use of statements of identity between objects of a certain kind.
     From: Michael Dummett (Frege Philosophy of Language (2nd ed) [1973], Ch.14)
     A reaction: This is the necessary Fregean preliminary to using a principle of abstraction to identify two objects which are abstract (when the two objects are in an equivalence relation). Presumably circular squares and square circles are identical?
There is no reason why abstraction by equivalence classes should be called 'logical' [Dummett, by Tait]
     Full Idea: Dummett uses the term 'logical abstraction' for the construction of the abstract objects as equivalence classes, but it is not clear why we should call this construction 'logical'.
     From: report of Michael Dummett (Frege philosophy of mathematics [1991]) by William W. Tait - Frege versus Cantor and Dedekind n 14
     A reaction: This is a good objection, and Tait offers a much better notion of 'logical abstraction' (as involving preconditions for successful inference), in Idea 9981.
We arrive at the concept 'suicide' by comparing 'Cato killed Cato' with 'Brutus killed Brutus' [Dummett]
     Full Idea: We arrive at the concept of suicide by considering both occurrences in the sentence 'Cato killed Cato' of the proper name 'Cato' as simultaneously replaceable by another name, say 'Brutus', and so apprehending the pattern common to both sentences.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.14)
     A reaction: This is intended to illustrate Frege's 'logical abstraction' technique, as opposed to wicked psychological abstraction. The concept of suicide is the pattern 'x killed x'. This is a crucial example if we are to understand abstraction...
18. Thought / E. Abstraction / 8. Abstractionism Critique
To abstract from spoons (to get the same number as the forks), the spoons must be indistinguishable too [Dummett]
     Full Idea: To get units by abstraction, units arrived at by abstraction from forks must the identical to that abstracted from spoons, with no trace of individuality. But if spoons can no longer be differentiated from forks, they can't differ from one another either.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 8)
     A reaction: [compressed] Dummett makes the point better than Frege did. Can we 'think of a fork insofar as it is countable, ignoring its other features'? What are we left thinking of? Frege says it must still be the whole fork. 'Nice fork, apart from the colour'.
To 'abstract from' is a logical process, as opposed to the old mental view [Dummett]
     Full Idea: The phrase 'abstracted from' does not refer to the mental process of abstraction by disregarding features of concrete objects, in which many nineteenth century thinkers believed; it is a logical (not mental) process of concept-formation.
     From: Michael Dummett (Thought and Reality [1997], 1)
     A reaction: I take Frege's attack on 'psychologism' to be what dismissed the old view (Idea 5816). Could one not achieve the same story by negating properties in quantified logical expressions, instead of in the mind?