55 ideas
| 21887 | Derrida focuses on other philosophers, rather than on science [Derrida] |
| Full Idea: We should focus on other philosophers, and not on science. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21888 | Philosophy is just a linguistic display [Derrida] |
| Full Idea: Philosophy is entirely linguistic, and is a display. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21896 | Philosophy aims to build foundations for thought [Derrida, by May] |
| Full Idea: Derrida points out that the project of philosophy consists largely in attempting to build foundations for thought. | |
| From: report of Jacques Derrida (works [1990]) by Todd May - Gilles Deleuze 1.04 | |
| A reaction: You would first need to be convinced that there could be such a thing as foundations for thinking. Derrida thinks the project is hopeless. I think of it more as building an ideal framework for thought. |
| 21893 | Philosophy is necessarily metaphorical, and its writing is aesthetic [Derrida] |
| Full Idea: All of philosophy is necessarily metaphorical, and hence aesthetic. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 18859 | Metaphysics is a quest for truthmakers [Tallant] |
| Full Idea: In this book I will treat metaphysics as a quest for truthmakers. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 01) | |
| A reaction: I find this appealing, though obviously you have to say what sort of truthmakers generate 'metaphysical' truths, as opposed to physics or biology. I take it that would involve truthmakers that had a high level of generality, idealisation and abstraction. |
| 21892 | Interpretations can be interpreted, so there is no original 'meaning' available [Derrida] |
| Full Idea: Because interpretations of texts can be interpreted, they can therefore have no 'original meaning'. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 20925 | Hermeneutics blunts truth, by conforming it to the interpreter [Derrida, by Zimmermann,J] |
| Full Idea: Derrida worried that hermeneutics blunts the disruptive power of truth by forcing it conform to the interpreter's mental horizon. | |
| From: report of Jacques Derrida (works [1990]) by Jens Zimmermann - Hermeneutics: a very short introduction 3 'The heart' | |
| A reaction: Good heavens - I agree with Derrida. Very French, though, to see the value of truth in its disruptiveness. I tend to find the truth reassuring, but then I'm English. |
| 20934 | Hermeneutics is hostile, trying to overcome the other person's difference [Derrida, by Zimmermann,J] |
| Full Idea: Derrida described the hermeneutic impulse to understand another as a form of violence that seeks to overcome the other's particularity and unique difference. | |
| From: report of Jacques Derrida (works [1990]) by Jens Zimmermann - Hermeneutics: a very short introduction App 'Derrida' | |
| A reaction: I'm not sure about 'violence', but Derrida was on to somethng here. The 'hermeneutic circle' sounds like a creepy process of absorption, where the original writer disappears in a whirlpool of interpretation. |
| 21895 | Structuralism destroys awareness of dynamic meaning [Derrida] |
| Full Idea: Structuralism destroys awareness of dynamic meaning. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21934 | The idea of being as persistent presence, and meaning as conscious intelligibility, are self-destructive [Derrida, by Glendinning] |
| Full Idea: The tradition of conceiving being in terms of persisting presence, and meaning in terms of pure intelligibility or logos potentially present to the mind, finds itself dismantled by resources internal to its own construction. | |
| From: report of Jacques Derrida (works [1990]) by Simon Glendinning - Derrida: A Very Short Introduction 6 | |
| A reaction: [compressed] Glendinning says this is the basic meaning of de-construction. My personal reading of this is that Aristotle is right, and grand talk of Being is hopeless, so we should just aim to understand objects. I also believe in propositions. |
| 21883 | Sincerity can't be verified, so fiction infuses speech, and hence reality also [Derrida] |
| Full Idea: Sincerity can never be verified, so fiction infuses all speech, which means that reality is also fictional. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21882 | Sentences are contradictory, as they have opposite meanings in some contexts [Derrida] |
| Full Idea: Sentences are implicitly contradictory, because they can be used differently in different contexts (most obviously in 'I am ill'). | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21881 | We aim to explore the limits of expression (as in Mallarmé's poetry) [Derrida] |
| Full Idea: The aim is to explore the limits of expression (which is what makes the poetry of Mallarmé so important). | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 18861 | Maybe number statements can be paraphrased into quantifications plus identities [Tallant] |
| Full Idea: One strategy is whenever we are presented with a sentence that might appear to entail the existence of numbers, all that we have to do is paraphrase it using a quantified logic, plus identity. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 03.5) | |
| A reaction: This nominalist strategy seems fine for manageable numbers, but gets in trouble with numbers too big to count (e.g. grains of sand in the world) , or genuine infinities. |
| 4756 | Derrida says that all truth-talk is merely metaphor [Derrida, by Engel] |
| Full Idea: Derrida's view is that every discourse is metaphorical, and there is no difference between truth-talk and metaphor. | |
| From: report of Jacques Derrida (works [1990]) by Pascal Engel - Truth §2.5 | |
| A reaction: Right. Note that this is a Frenchman's summary. How would one define metaphor, without mentioning that it is parasitic on truth? Certainly some language tries to be metaphor, and other language tries not to be. |
| 21877 | True thoughts are inaccessible, in the subconscious, prior to speech or writing [Derrida] |
| Full Idea: 'True' thoughts are inaccessible, buried in the subconscious, long before they get to speech or writing. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction | |
| A reaction: [My reading of some Derrida produced no quotations. I've read two commentaries, which were obscure. The Derrida ideas in this db are my simplistic tertiary summaries. Experts can chuckle over my failure] |
| 18866 | Maybe only 'positive' truths need truth-makers [Tallant] |
| Full Idea: We might say that those truths that do not need truth-makers are those that are negative. Those that do need truth-makers are those that are positive. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 10.8) | |
| A reaction: If you deny the existence of something, there is always an implicit domain for the denial, such as 'on the table', or 'in this building', or 'in the cosmos'. So why can't that domain be the truthmaker for a negative existential? |
| 18860 | A truthmaker is the minimal portion of reality that will do the job [Tallant] |
| Full Idea: A 'minimal' truth-maker is the 'smallest' portion of reality required to make a given proposition true. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 01.2) | |
| A reaction: A nice suggestion. This seems to make Ockham's Razor an integral part of the theory of truth-makers. I would apply the same principle to explanations. An Ockhamist explanation is what explains the puzzling thing - and nothing else. |
| 18863 | What is the truthmaker for a possible new power? [Tallant] |
| Full Idea: What power will make true 'there could be a power that does not in fact exist'? | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 04.13) | |
| A reaction: Nice question. We can't know whether it is true that a new power could exist, so we can't expect an actual truthmaker for it. Though we might predict new powers (such as for a new transuranic element), on the basis of the known ones. |
| 13520 | A 'tautology' must include connectives [Wolf,RS] |
| Full Idea: 'For every number x, x = x' is not a tautology, because it includes no connectives. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.2) |
| 13524 | Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS] |
| Full Idea: Deduction Theorem: If T ∪ {P} |- Q, then T |- (P → Q). This is the formal justification of the method of conditional proof (CPP). Its converse holds, and is essentially modus ponens. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.3) |
| 13522 | Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS] |
| Full Idea: Universal Generalization: If we can prove P(x), only assuming what sort of object x is, we may conclude ∀xP(x) for the same x. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.3) | |
| A reaction: This principle needs watching closely. If you pick one person in London, with no presuppositions, and it happens to be a woman, can you conclude that all the people in London are women? Fine in logic and mathematics, suspect in life. |
| 13521 | Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS] |
| Full Idea: Universal Specification: from ∀xP(x) we may conclude P(t), where t is an appropriate term. If something is true for all members of a domain, then it is true for some particular one that we specify. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.3) |
| 13523 | Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS] |
| Full Idea: Existential Generalization (or 'proof by example'): From P(t), where t is an appropriate term, we may conclude ∃xP(x). | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.3) | |
| A reaction: It is amazing how often this vacuous-sounding principles finds itself being employed in discussions of ontology, but I don't quite understand why. |
| 13529 | Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS] |
| Full Idea: Empty Set Axiom: ∃x ∀y ¬ (y ∈ x). There is a set x which has no members (no y's). The empty set exists. There is a set with no members, and by extensionality this set is unique. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 2.3) | |
| A reaction: A bit bewildering for novices. It says there is a box with nothing in it, or a pair of curly brackets with nothing between them. It seems to be the key idea in set theory, because it asserts the idea of a set over and above any possible members. |
| 13526 | Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS] |
| Full Idea: The comprehension axiom says that any collection of objects that can be clearly specified can be considered to be a set. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 2.2) | |
| A reaction: This is virtually tautological, since I presume that 'clearly specified' means pinning down exact which items are the members, which is what a set is (by extensionality). The naïve version is, of course, not so hot. |
| 13534 | In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS] |
| Full Idea: One of the most appealing features of first-order logic is that the two 'turnstiles' (the syntactic single |-, and the semantic double |=), which are the two reasonable notions of logical consequence, actually coincide. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.3) | |
| A reaction: In the excitement about the possibility of second-order logic, plural quantification etc., it seems easy to forget the virtues of the basic system that is the target of the rebellion. The issue is how much can be 'expressed' in first-order logic. |
| 13535 | First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS] |
| Full Idea: The 'completeness' of first order-logic does not mean that every sentence or its negation is provable in first-order logic. We have instead the weaker result that every valid sentence is provable. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.3) | |
| A reaction: Peter Smith calls the stronger version 'negation completeness'. |
| 21889 | 'I' is the perfect name, because it denotes without description [Derrida] |
| Full Idea: 'I' is the perfect name, because it denotes without description. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21878 | Names have a subjective aspect, especially the role of our own name [Derrida] |
| Full Idea: We can give a subjective account of names, by considering our own name. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21879 | Even Kripke can't explain names; the word is the thing, and the thing is the word [Derrida] |
| Full Idea: Even Kripke can't explain names, because the word is the thing, and also the thing is the word. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 13532 | Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS] |
| Full Idea: A 'structure' in model theory has a non-empty set, the 'universe', as domain of variables, a subset for each 'relation', some 'functions', and 'constants'. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.2) |
| 13519 | Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS] |
| Full Idea: Model theory uses set theory to show that the theorem-proving power of the usual methods of deduction in mathematics corresponds perfectly to what must be true in actual mathematical structures. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], Pref) | |
| A reaction: That more or less says that model theory demonstrates the 'soundness' of mathematics (though normal arithmetic is famously not 'complete'). Of course, he says they 'correspond' to the truths, rather than entailing them. |
| 13533 | First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS] |
| Full Idea: The three foundations of first-order model theory are the Completeness theorem, the Compactness theorem, and the Löwenheim-Skolem-Tarski theorem. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.3) | |
| A reaction: On p.180 he notes that Compactness and LST make no mention of |- and are purely semantic, where Completeness shows the equivalence of |- and |=. All three fail for second-order logic (p.223). |
| 13531 | Model theory reveals the structures of mathematics [Wolf,RS] |
| Full Idea: Model theory helps one to understand what it takes to specify a mathematical structure uniquely. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.1) | |
| A reaction: Thus it is the development of model theory which has led to the 'structuralist' view of mathematics. |
| 13537 | An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS] |
| Full Idea: An 'isomorphism' is a bijection between two sets that preserves all structural components. The interpretations of each constant symbol are mapped across, and functions map the relation and function symbols. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.4) |
| 13539 | The LST Theorem is a serious limitation of first-order logic [Wolf,RS] |
| Full Idea: The Löwenheim-Skolem-Tarski theorem demonstrates a serious limitation of first-order logic, and is one of primary reasons for considering stronger logics. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.7) |
| 13538 | If a theory is complete, only a more powerful language can strengthen it [Wolf,RS] |
| Full Idea: It is valuable to know that a theory is complete, because then we know it cannot be strengthened without passing to a more powerful language. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 5.5) |
| 13525 | Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS] |
| Full Idea: Deductive logic, including first-order logic and other types of logic used in mathematics, is 'monotonic'. This means that we never retract a theorem on the basis of new givens. If T|-φ and T⊆SW, then S|-φ. Ordinary reasoning is nonmonotonic. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 1.7) | |
| A reaction: The classic example of nonmonotonic reasoning is the induction that 'all birds can fly', which is retracted when the bird turns out to be a penguin. He says nonmonotonic logic is a rich field in computer science. |
| 13530 | An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS] |
| Full Idea: Less theoretically, an ordinal is an equivalence class of well-orderings. Formally, we say a set is 'transitive' if every member of it is a subset of it, and an ordinal is a transitive set, all of whose members are transitive. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], 2.4) | |
| A reaction: He glosses 'transitive' as 'every member of a member of it is a member of it'. So it's membership all the way down. This is the von Neumann rather than the Zermelo approach (which is based on singletons). |
| 13518 | Modern mathematics has unified all of its objects within set theory [Wolf,RS] |
| Full Idea: One of the great achievements of modern mathematics has been the unification of its many types of objects. It began with showing geometric objects numerically or algebraically, and culminated with set theory representing all the normal objects. | |
| From: Robert S. Wolf (A Tour through Mathematical Logic [2005], Pref) | |
| A reaction: His use of the word 'object' begs all sorts of questions, if you are arriving from the street, where an object is something which can cause a bruise - but get used to it, because the word 'object' has been borrowed for new uses. |
| 18864 | The wisdom of Plato and of Socrates are not the same property [Tallant] |
| Full Idea: It is not the case that Plato's wisdom = Socrates's wisdom. Platonic-wisdom and Socratic-wisdom are not the same property. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 05.4) | |
| A reaction: This seems reasonable in the case of wisdom, but not so clear in the case of indistinguishable properties of redness or squareness or mass. Nevertheless it gives nice support for trope theory. |
| 18865 | Substance must have two properties: individuation, and property-bearing [Tallant] |
| Full Idea: It appears that substance has essential properties: it is of the essence of substance that it individuates, and it is of the essence of substance that it bears properties. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 06.2) | |
| A reaction: The point being that substances are not 'bear', because they have a role to perform, and a complete blank can't fulfil a role. We can't take substance, though, seriously in ontology. It is just a label for distinct individuals. |
| 21890 | Heidegger showed that passing time is the key to consciousness [Derrida] |
| Full Idea: Heidegger showed us the importance of transient time for consciousness. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21880 | 'Tacit theory' controls our thinking (which is why Freud is important) [Derrida] |
| Full Idea: All thought is controlled by tacit theory (which is why Freud is so important). | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction | |
| A reaction: This idea is said to be the essential thought of Derrida's Deconstruction. The aim is liberation of thought, by identifying and bypassing these tacit metaphysical schemas. |
| 21886 | Meanings depend on differences and contrasts [Derrida] |
| Full Idea: Meaning depends on 'differences' (contrasts). | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21930 | For Aristotle all proper nouns must have a single sense, which is the purpose of language [Derrida] |
| Full Idea: A noun [for Aristotle] is proper when it has but a single sense. Better, it is only in this case that it is properly a noun. Univocity is the essence, or better, the telos of language. | |
| From: Jacques Derrida (works [1990]), quoted by Simon Glendinning - Derrida: A Very Short Introduction 5 | |
| A reaction: [no ref given] His target seem to be Aristotelian definition, and also formal logic, which usually needs unambiguous meanings. {I'm puzzled that he thinks 'telos' is simply better than 'essence', since it is quite different]. |
| 21884 | Capacity for repetitions is the hallmark of language [Derrida] |
| Full Idea: The capacity for repetitions is the hallmark of language. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21935 | The sign is only conceivable as a movement between elusive presences [Derrida] |
| Full Idea: The sign is conceivable only on the basis of the presence that it defers, and moving toward the deferred presence that it aims to reappropriate. | |
| From: Jacques Derrida (works [1990]), quoted by Simon Glendinning - Derrida: A Very Short Introduction 6 | |
| A reaction: [Glendinning gives no source for this] I take the fundamental idea to be that meanings are dynamic, when they are traditionally understood as static (and specifiable in dictionaries). |
| 21933 | Writing functions even if the sender or the receiver are absent [Derrida, by Glendinning] |
| Full Idea: Writing can and must be able to do without the presence of the sender. ...Also writing can and must he able to do without the presence of the receiver. | |
| From: report of Jacques Derrida (works [1990]) by Simon Glendinning - Derrida: A Very Short Introduction 6 | |
| A reaction: In simple terms, one of them could die during the transmission. This is the grounds for the assertion of the primacy of writing. It opposes orthodox views which define language in terms of sender and receiver. |
| 21894 | Madness and instability ('the demonic hyperbole') lurks in all language [Derrida] |
| Full Idea: Madness and instability ('the demonic hyperbole') lurks behind all language. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 21931 | 'Dissemination' is opposed to polysemia, since that is irreducible, because of multiple understandings [Derrida, by Glendinning] |
| Full Idea: The intention to oppose polysemia with dissemination does not aim to affirm that everything we say is ambiguous, but that polysemia is irreducible in the sense that each and every 'meaning' is itself subject to more than one understanding. | |
| From: report of Jacques Derrida (works [1990]) by Simon Glendinning - Derrida: A Very Short Introduction 5 | |
| A reaction: The key point, I think, is that ambiguity and polysemia are not failures of language (which is the way most logicians see it), but part of the essential and irreducible nature of language. Nietzsche started this line of thought. |
| 21885 | Words exist in 'spacing', so meanings are never synchronic except in writing [Derrida] |
| Full Idea: Words only exist is 'spacings' (of time and space), so there are no synchronic meanings (except perhaps in writing). | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |
| 18862 | Are propositions all the thoughts and sentences that are possible? [Tallant] |
| Full Idea: One might be tempted to the view that there are as many different propositions as there are thoughts that could be thought and sentences that could be uttered. | |
| From: Jonathan Tallant (Metaphysics: an introduction [2011], 04.5.3) | |
| A reaction: A fairly orthodox view I take to be crazy. I think it is a view designed for logic, rather than for how the world is. Why tie propositions to what can be thought, and then introduce unthought propositions? Why no unthinkable propositions? |
| 21891 | The good is implicitly violent (against evil), so there is no pure good [Derrida] |
| Full Idea: Even the good is implicitly violent (against evil), so there can be no 'pure' good. | |
| From: Jacques Derrida (works [1990]), quoted by Barry Stocker - Derrida on Deconstruction |