15 ideas
23291 | Without truth, both language and thought are impossible [Davidson] |
Full Idea: Without a grasp of the concept of truth, not only language, but thought itself, is impossible. | |
From: Donald Davidson (Truth Rehabilitated [1997], p.16) | |
A reaction: Davidson never mentions animals, but I like this idea because it points to importance of truth for animals as well. I say that truth is relevant to any mind that makes judgements - and quite small animals (e.g. ants and spiders) make judgements. |
23284 | Plato's Forms confused truth with the most eminent truths, so only Truth itself is completely true [Davidson] |
Full Idea: Plato's conflation of abstract universals with entities of supreme value reinforced the confusion of truth with the most eminent truths. …The only perfect exemplar of a Form is the Form itself, …and only truth itself is completely true. | |
From: Donald Davidson (Truth Rehabilitated [1997], p.3) | |
A reaction: Even non-subscribers to Plato often talk as if there were some grand thing called the Truth with a capital T, quite often used in a religious context. Truth is the hallmark of successful (non-fanciful) thought. |
23286 | Truth can't be a goal, because we can neither recognise it nor confim it [Davidson] |
Full Idea: Since it is neither visible as a target, nor recognisable when achieved, there is no point in calling truth a goal. We should only aim at increasing confidence in our beliefs, by collecting further evidence or checking our calculations. | |
From: Donald Davidson (Truth Rehabilitated [1997], P.6) | |
A reaction: This is mainly aimed at pragmatists, but Davidson obviously subscribes (as do I) to their fallibilist view of knowledge. |
23292 | Correspondence can't be defined, but it shows how truth depends on the world [Davidson] |
Full Idea: Correspondence, while it is empty as a definition, does capture the thought that truth depends on how the world is. | |
From: Donald Davidson (Truth Rehabilitated [1997], p.16) | |
A reaction: Just don't try to give a precise account of the correspondence between two things (thoughts and facts) which are so utterly different in character. |
23288 | When Tarski defines truth for different languages, how do we know it is a single concept? [Davidson] |
Full Idea: We have to wonder how we know that it is some single concept which Tarski indicates how to define for each of a number of well-behaved languages. | |
From: Donald Davidson (Truth Rehabilitated [1997], P.11) | |
A reaction: Davidson says that Tarski makes the assumption that it is a single concept, but fails to demonstrate the fact. This resembles Frege's Julius Caesar problem - of how you know whether your number definition has defined a number. |
23287 | Disquotation only accounts for truth if the metalanguage contains the object language [Davidson] |
Full Idea: Disquotation cannot pretend to give a complete account of the concept of truth, since it works only in the special case where the metalanguage contains the object language. Neither can contain their own truth predicate. | |
From: Donald Davidson (Truth Rehabilitated [1997], p.10) | |
A reaction: Presumably more sophisticated and complete accounts would need a further account of translation between languages - which explains Quine's interest in that topic. […see this essay, p.12] |
17818 | How many? must first partition an aggregate into sets, and then logic fixes its number [Yourgrau] |
Full Idea: We want to know How many what? You must first partition an aggregate into parts relevant to the question, where no partition is privileged. How the partitioned set is to be numbered is bound up with its unique members, and follows from logic alone. | |
From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'New Problem') | |
A reaction: [Compressed wording of Yourgrau's summary of Frege's 'relativity argument'] Concepts do the partitioning. Yourgau says this fails, because the same argument applies to the sets themselves, as well as to the original aggregates. |
17822 | Nothing is 'intrinsically' numbered [Yourgrau] |
Full Idea: Nothing at all is 'intrinsically' numbered. | |
From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'What the') | |
A reaction: Once you are faced with distinct 'objects' of some sort, they can play the role of 'unit' in counting, so his challenge is that nothing is 'intrinsically' an object, which is the nihilism explored by Unger, Van Inwagen and Merricks. Aristotle disagrees... |
17817 | Defining 'three' as the principle of collection or property of threes explains set theory definitions [Yourgrau] |
Full Idea: The Frege-Maddy definition of number (as the 'property' of being-three) explains why the definitions of Von Neumann, Zermelo and others work, by giving the 'principle of collection' that ties together all threes. | |
From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'A Fregean') | |
A reaction: [compressed two or three sentences] I am strongly in favour of the best definition being the one which explains the target, rather than just pinning it down. I take this to be Aristotle's view. |
17815 | We can't use sets as foundations for mathematics if we must await results from the upper reaches [Yourgrau] |
Full Idea: Sets could hardly serve as a foundation for number theory if we had to await detailed results in the upper reaches of the edifice before we could make our first move. | |
From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'Two') |
17821 | You can ask all sorts of numerical questions about any one given set [Yourgrau] |
Full Idea: We can address a set with any question at all that admits of a numerical reply. Thus we can ask of {Carter, Reagan} 'How many feet do the members have?'. | |
From: Palle Yourgrau (Sets, Aggregates and Numbers [1985], 'On Numbering') | |
A reaction: This is his objection to the Fregean idea that once you have fixed the members of a set, you have thereby fixed the unique number that belongs with the set. |
23285 | If we try to identify facts precisely, they all melt into one (as the Slingshot Argument proves) [Davidson] |
Full Idea: If we try to provide a serious semantics for reference to facts, we discover that they melt into one; there is no telling them apart. The relevant argument (the 'Slingshot') was credited to Frege by Alonso Church. | |
From: Donald Davidson (Truth Rehabilitated [1997], p.5) | |
A reaction: This sounds like good grounds for not attempting to be too precise. 'There are bluebells in my local wood' identifies a fact by words, but even an animal can distinguish this fact. Only a logician dreams of making its content precise. |
23289 | Knowing the potential truth conditions of a sentence is necessary and sufficient for understanding [Davidson] |
Full Idea: It is clear that someone who knows under what conditions a sentence would be true understands that sentence, …and if someone does not know under what conditions it would be true then they do not understand it. | |
From: Donald Davidson (Truth Rehabilitated [1997], p.13) | |
A reaction: I've always subscribed to this view. Langauge is meaningless if you can't relate it to reality, and I don't think there could be a language without an intuitive notion of truth. |
23290 | It could be that the use of a sentence is explained by its truth conditions [Davidson] |
Full Idea: It may be that sentences are used as they are because of their truth conditions, and they have the truth conditions they do because of how they are used. | |
From: Donald Davidson (Truth Rehabilitated [1997], p.13) | |
A reaction: I've always taken the attempt to explain meaning by use as absurd. It is similar to trying to explain mind in terms of function. In each case, what is the intrinsic nature of the thing, which makes that use or that function possible? |
1743 | The greatest deterrence for injustice is if uninjured parties feel as much indignation as those who are injured [Solon, by Diog. Laertius] |
Full Idea: Men can be most effectively deterred from committing injustice if those who are not injured feel as much indignation as those who are. | |
From: report of Solon (reports [c.600 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 01.So.10 |