display all the ideas for this combination of philosophers
9 ideas
13342 | Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap] |
Full Idea: Carnap proposed to define consequence as 'sentence X follows from the sentences K iff the sentences K and the negation of X are contradictory', but 1) this is intuitively impossible, and 2) consequence would be changed by substituting objects. | |
From: comment on Rudolph Carnap (The Logical Syntax of Language [1934], p.88-) by Alfred Tarski - The Concept of Logical Consequence p.414 | |
A reaction: This seems to be the first step in the ongoing explicit discussion of the nature of logical consequence, which is now seen by many as the central concept of logic. Tarski brings his new tool of 'satisfaction' to bear. |
13251 | Each person is free to build their own logic, just by specifying a syntax [Carnap] |
Full Idea: In logic, there are no morals. Everyone is at liberty to build his own logic, i.e. his own form of language. All that is required is that he must state his methods clearly, and give syntactical rules instead of philosophical arguments. | |
From: Rudolph Carnap (The Logical Syntax of Language [1934], §17), quoted by JC Beall / G Restall - Logical Pluralism 7.3 | |
A reaction: This is understandable, but strikes me as close to daft relativism. If I specify a silly logic, I presume its silliness will be obvious. By what criteria? I say the world dictates the true logic, but this is a minority view. |
13777 | A name is a sort of tool [Plato] |
Full Idea: A name is a sort of tool. | |
From: Plato (Cratylus [c.377 BCE], 388a) | |
A reaction: Idea 13775 gives a background for this metaphor, from earlier in the text. Wittgenstein has a famous toolkit metaphor for language. The whole of this text, 'Cratylus', is about names. |
13790 | A name-giver might misname something, then force other names to conform to it [Plato] |
Full Idea: The name-giver might have made a mistake at the beginning and then forced the other names to be consistent with it. | |
From: Plato (Cratylus [c.377 BCE], 436c) | |
A reaction: Lovely. This is Gareth Evans's 'Madagascar' example. See Idea 9041. |
13791 | Things must be known before they are named, so it can't be the names that give us knowledge [Plato] |
Full Idea: If things cannot be learned except from their names, how can we possibly claim that the name-givers or rule-setters have knowledge before any names had been given for them to know? | |
From: Plato (Cratylus [c.377 BCE], 438b) | |
A reaction: Running through this is a hostility to philosophy of language, so I find it very congenial. We are animals who relate to the world before language takes a grip. We have full-blown knowledge of things, with no intervention of words. |
13789 | Anyone who knows a thing's name also knows the thing [Plato] |
Full Idea: The simple truth is that anyone who knows a thing's name also knows the thing. | |
From: Plato (Cratylus [c.377 BCE], 435d) | |
A reaction: A nice slogan, but it seems to be blatantly false. The best example is Gareth Evans's of joining in a conversation about a person ('Louis'?), and only gradually tuning in to the person to which the name refers. |
11259 | How can you seek knowledge of something if you don't know it? [Plato] |
Full Idea: How will you aim to search for something you do not know at all? If you should meet with it, how will you know that this is the thing that you did not know? | |
From: Plato (Meno [c.385 BCE], 80d05) | |
A reaction: Vasilis Politis cites this as a nice example of the 'aporiai' (puzzles) which Aristotle said were the foundation of enquiry. Nowadays the problem is called the 'paradox of enquiry'. |
13986 | Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle] |
Full Idea: Plato (in 'Parmenides') shows that the theory that 'Eide' are substances, and Kant that space and time are substances, and Bradley that relations are substances, all lead to aninomies. | |
From: report of Plato (Parmenides [c.364 BCE]) by Gilbert Ryle - Are there propositions? 'Objections' |
14150 | Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato] |
Full Idea: Plato's 'Parmenides' is perhaps the best collection of antinomies ever made. | |
From: comment on Plato (Parmenides [c.364 BCE]) by Bertrand Russell - The Principles of Mathematics §337 |