28 ideas
22285 | Impredicative definitions are circular, but fine for picking out, rather than creating something [Potter] |
Full Idea: The circularity in a definition where the property being defined is used in the definition is now known as 'impredicativity'. ...Some cases ('the tallest man in the room') are unproblematic, as they pick him out, and don't conjure him into existence. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 07 'Impred') | |
A reaction: [part summary] |
22301 | The Identity Theory says a proposition is true if it coincides with what makes it true [Potter] |
Full Idea: The Identity Theory of truth says a proposition is true just in case it coincides with what makes it true. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 23 'Abs') | |
A reaction: The obvious question is how 'there are trees in the wood' can somehow 'coincide with' or 'be identical to' the situation outside my window. The theory is sort of right, but we will never define the relationship, which is no better than 'corresponds'. |
22324 | It has been unfortunate that externalism about truth is equated with correspondence [Potter] |
Full Idea: There has been an unfortunate tendency in the secondary literature to equate externalism about truth with the correspondence theory. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 65 'Truth') | |
A reaction: Quite helpful to distinguish internalist from externalist theories of truth. It is certainly the case that robust externalist views of truth have unfortunately been discredited merely because the correspondence account is inadequate. |
22279 | Frege's sign |--- meant judgements, but the modern |- turnstile means inference, with intecedents [Potter] |
Full Idea: Natural deduction systems generally depend on conditional proof, but for Frege everything is asserted unconditionally. The modern turnstile |- is allowed to have antecedents, and hence to represent inference rather than Frege's judgement sign |---. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 03 'Axioms') | |
A reaction: [compressed] Shockingly, Frege's approach seems more psychological than the modern approach. I would say that the whole point of logic is that it has to be conditional, because the truth of the antecedents is irrelevant. |
22291 | Deductivism can't explain how the world supports unconditional conclusions [Potter] |
Full Idea: Deductivism is a good account of large parts of mathematics, but stumbles where mathematics is directly applicable to the world. It fails to explain how we detach the antecedent so as to arrive at unconditional conclusions. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 12 'Deduc') | |
A reaction: I suppose the reply would be that we have designed deductive structures which fit our understanding of reality - so it is all deductive, but selected pragmatically. |
22295 | Modern logical truths are true under all interpretations of the non-logical words [Potter] |
Full Idea: In the modern definition, a 'logical truth' is true under every interpretation of the non-logical words it contains. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 19 'Frege's') | |
A reaction: What if the non-logical words are nonsense, or are used inconsistently ('good'), or ambiguously ('bank'), or vaguely ('bald'), or with unsure reference ('the greatest philosopher' becomes 'Bentham')? What qualifies as an 'interpretation'? |
8463 | Maths can be reduced to logic and set theory [Quine] |
Full Idea: Researches in the foundations of mathematics have made it clear that all of (interpreted) mathematics can be got down to logic and set theory, and the objects needed for mathematics can be got down to the category of classes (and classes of classes..). | |
From: Willard Quine (The Scope and Language of Science [1954], §VI) | |
A reaction: This I take to be a retreat from pure logicism, presumably influenced by Gödel. So can set theory be reduced to logic? Crispin Wright is the one the study. |
22310 | The formalist defence against Gödel is to reject his metalinguistic concept of truth [Potter] |
Full Idea: Gödel's theorem does not refute formalism outright, because the committed formalist need not recognise the metalinguistic notion of truth to which the theorem appeals. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 45 'Log') | |
A reaction: The theorem was prior to Tarski's account of truth. Potter says Gödel avoided explicit mention of truth because of this problem. In general Gödel showed that there are truths outside the formal system (which is all provable). |
22298 | Why is fictional arithmetic applicable to the real world? [Potter] |
Full Idea: Fictionalists struggle to explain why arithmetic is applicable to the real world in a way that other stories are not. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 21 'Math') | |
A reaction: We know why some novels are realistic and others just the opposite. If a novel aimed to 'model' the real world it would be even closer to it. Fictionalists must explain why some fictions are useful. |
22287 | If 'concrete' is the negative of 'abstract', that means desires and hallucinations are concrete [Potter] |
Full Idea: The word 'concrete' is often used as the negative of 'abstract', with the slightly odd consequence that desires and hallucinations are thereby classified as concrete. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 12 'Numb') | |
A reaction: There is also the even more baffling usage of 'abstract' for the most highly generalised mathematics, leaving lower levels as 'concrete'. I favour the use of 'generalised' wherever possible, rather than 'abstract'. |
22284 | 'Greater than', which is the ancestral of 'successor', strictly orders the natural numbers [Potter] |
Full Idea: From the successor function we can deduce its ancestral, the 'greater than' relation, which is a strict total ordering of the natural numbers. (Frege did not mention this, but Dedekind worked it out, when expounding definition by recursion). | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 07 'Def') | |
A reaction: [compressed] |
8461 | The category of objects incorporates the old distinction of substances and their modes [Quine] |
Full Idea: The category of objects embraces indiscriminately what would anciently have been distinguished as substances and as modes or states of substances. | |
From: Willard Quine (The Scope and Language of Science [1954], §6) | |
A reaction: This nicely captures Quine's elimination of properties, by presenting them as inseparable from their objects/substances. Armstrong calls this 'Ostrich Nominalism' (for refusing to address the universals problem) but Quineans are unshaken. |
22281 | A material conditional cannot capture counterfactual reasoning [Potter] |
Full Idea: What the material conditional most significantly fails to capture is counterfactual reasoning. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 04 'Sem') | |
A reaction: The point is that counterfactuals say 'if P were the case (which it isn't), then Q'. But that means P is false, and in the material conditional everything follows from a falsehood. A reinterpretation of the conditional might embrace counterfactuals. |
22327 | Knowledge from a drunken schoolteacher is from a reliable and unreliable process [Potter] |
Full Idea: Knowledge might result from a reliable and an unreliable process. ...Is something knowledge if you were told it by a drunken schoolteacher? | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 66 'Rel') | |
A reaction: Nice example. The listener must decide which process to rely on. But how do you decide that, if not by assessing the likely truth of what you are being told? It could be a bad teacher who is inspired by drink. |
8462 | A hallucination can, like an ague, be identified with its host; the ontology is physical, the idiom mental [Quine] |
Full Idea: A physical ontology has a place for states of mind. An inspiration or a hallucination can, like the fit of ague, be identified with its host for the duration. It leaves our mentalistic idioms fairly intact, but reconciles them with a physical ontology. | |
From: Willard Quine (The Scope and Language of Science [1954], §VI) | |
A reaction: Quine is employing the same strategy that he uses for substances and properties (Idea 8461): take the predication as basic, rather than reifying the thing being predicated. The ague analogy suggests that Quine is an incipient functionalist. |
22273 | Traditionally there are twelve categories of judgement, in groups of three [Potter] |
Full Idea: The traditional categorisation of judgements (until at least 1800) was as universal, particular or singular; as affirmative, negative or infinite; as categorical, hypothetical or disjunctive; or as problematic, assertoric or apodictic. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 02 'Trans') | |
A reaction: Arranging these things in neat groups of three seems to originate with the stoics. Making distinctions like this is very much the job of a philosopher, but arranging them in neat equinumerous groups is intellectual tyranny. |
22290 | The phrase 'the concept "horse"' can't refer to a concept, because it is saturated [Potter] |
Full Idea: Frege's mirroring principle (that the structure of thoughts mirrors that of language) has the uncomfortable consequence that since the phrase 'the concept "horse"' is saturated, it cannot refer to something unsaturated, which includes concepts. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 16 'Conc') |
22283 | Compositionality should rely on the parsing tree, which may contain more than sentence components [Potter] |
Full Idea: Compositionality is best seen as saying the semantic value of a string is explained by the strings lower down its parsing tree. It is unimportant whether a string is always parsed in terms of its own substrings. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 05 'Sem') | |
A reaction: That is, the analysis must explain the meaning, but the analysis can contain more than the actual ingredients of the sentence (which would be too strict). |
22282 | 'Direct compositonality' says the components wholly explain a sentence meaning [Potter] |
Full Idea: Some authors urge the strong notion of 'direct compositionality', which requires that the content of a sentence be explained in terms of the contents of the component parts of that very sentence. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 05 'Sem') | |
A reaction: The alternative is that meaning is fully explained by an analysis, but that may contain more than the actual components of the sentence. |
22296 | Compositionality is more welcome in logic than in linguistics (which is more contextual) [Potter] |
Full Idea: The principle of compositionality is more popular among philosophers of logic than of language, because the subtle context-sensitivity or ordinary language makes providing a compositional semantics for it a daunting challenge. | |
From: Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 21 'Lang') | |
A reaction: Logicians love breaking complex entities down into simple atomic parts. Linguistics tries to pin down something much more elusive. |
7590 | Consequentialism emphasises value rather than obligation in morality [Scruton] |
Full Idea: According to consequentialism, the fundamental concept of morality is not obligation (deontological ethics) but value (axiological ethics). | |
From: Roger Scruton (A Dictionary of Political Thought [1982], 'consequentialism') | |
A reaction: These two views could come dramatically apart, in wartime, or in big ecological crises, or in a family breakup, or in religious disputes. Having identified the pair so clearly, why can we not aim for a civilised (virtuous) balance between the two? |
7589 | Altruism is either emotional (where your interests are mine) or moral (where they are reasons for me) [Scruton] |
Full Idea: Two distinct motives go by the name of altruism: the emotions of liking, love and friendship, making another's interest automatically mine; and the moral motive of respect or considerateness, where another's interests become reasons for me, but not mine. | |
From: Roger Scruton (A Dictionary of Political Thought [1982], 'altruism') | |
A reaction: The second one has a strongly Kantian flavour, with its notion of impersonal duty. Virtue theorists will aspire to achieve the first state rather than the second, because good actions are then actively desired, and give pleasure to the doer. |
7595 | The idea of a right seems fairly basic; justice may be the disposition to accord rights to people [Scruton] |
Full Idea: The idea of a right seems to be as basic as any other; we might even define justice in terms of it, as the disposition to accord to every person his rights. | |
From: Roger Scruton (A Dictionary of Political Thought [1982], 'rights') | |
A reaction: I am inclined to think that a set of fairly pure values (such as equality, kindness, sympathy, respect) must be in place before the idea of a right would occur to anyone. Aristotle has a powerful moral sense, but rights for slaves don't cross his mind. |
7588 | Allegiance is fundamental to the conservative view of society [Scruton] |
Full Idea: Conservatives have made the concept of allegiance, conceived as a power, fundamental to their description of the experience of society | |
From: Roger Scruton (A Dictionary of Political Thought [1982], 'allegiance') | |
A reaction: This provokes the famous slogan of "My country - right or wrong!" However, the issue here is not going to be decided by a consequentialist analysis, but by a view a of human nature. I think I would want to carefully prise allegiance apart from loyalty. |
7594 | Democrats are committed to a belief and to its opposite, if the majority prefer the latter [Scruton] |
Full Idea: The paradox of democracy (emphasised by Rousseau) is that I am compelled by my belief in democracy to embrace conflicting - perhaps even contradictory - opinions. If I believe A, and the majority vote for B, I am committed to enacting them both. | |
From: Roger Scruton (A Dictionary of Political Thought [1982], 'paradox of democracy') | |
A reaction: The paradox would have to be resolved by qualifying what exactly one is committed to by being a democrat. I would say I am committed to the right of my opponents to enact a policy with which I disagree. |
7593 | Liberals focus on universal human freedom, natural rights, and tolerance [Scruton, by PG] |
Full Idea: Liberalism believes (roughly) in the supremacy of the individual, who has freedom and natural rights; it focuses on human, not divine affairs; it claims rights and duties are universal; and it advocates tolerance in religion and morality. | |
From: report of Roger Scruton (A Dictionary of Political Thought [1982], 'liberalism') by PG - Db (ideas) | |
A reaction: I find it hard to disagree with these principles, but the upshot in practice is often an excessive commitment to freedom and tolerance, because people fail to realise the subtle long-term erosions of society that can result. |
7592 | For positivists law is a matter of form, for naturalists it is a matter of content [Scruton] |
Full Idea: For the positivist, law is law by virtue of its form; for the naturalist, by virtue of its content. | |
From: Roger Scruton (A Dictionary of Political Thought [1982], 'law') | |
A reaction: Clearly a perverse and 'unnatural' social rule (backed by government and implied force) is a 'law' in some sense of the word. It is hard to see how you could gain social consensus for a law if it didn't appear in some way to be 'natural justice'. |
7587 | The issue of abortion seems insoluble, because there is nothing with which to compare it [Scruton] |
Full Idea: The issue of abortion is intractable, partly because of the absence of any other case to which it can be assimilated. | |
From: Roger Scruton (A Dictionary of Political Thought [1982], 'abortion') | |
A reaction: This is the legalistic approach to the problem, which always looks for precedents and comparisons. All problems must hav solutions, though (mustn't they?). The problem, though, is not the value of the foetus, but the unique form of 'ownership'. |