38 ideas
12330 | In ontology, logic dominated language, until logic was mathematized [Badiou] |
Full Idea: From Aristotle to Hegel, logic was the philosophical category of ontology's dominion over language. The mathematization of logic has authorized language to become that which seizes philosophy for itself. | |
From: Alain Badiou (Briefings on Existence [1998], 8) |
9808 | Philosophy aims to reveal the grandeur of mathematics [Badiou] |
Full Idea: Philosophy's role consists in informing mathematics of its own speculative grandeur. | |
From: Alain Badiou (Mathematics and Philosophy: grand and little [2004], p.11) | |
A reaction: Revealing the grandeur of something sounds more like a rhetorical than a rational exercise. How would you reveal the grandeur of a sunset to someone? |
12318 | The female body, when taken in its entirety, is the Phallus itself [Badiou] |
Full Idea: The female body, when taken in its entirety, is the Phallus itself. | |
From: Alain Badiou (Briefings on Existence [1998]) | |
A reaction: Too good to pass over, too crazy to file sensibly, too creepy to have been filed under humour, my candidate for the weirdest remark I have ever read in a serious philosopher, but no doubt if you read Lacan etc for long enough it looks deeply wise. |
12325 | Philosophy has been relieved of physics, cosmology, politics, and now must give up ontology [Badiou] |
Full Idea: Philosophy has been released from, even relieved of, physics, cosmology, and politics, as well as many other things. It is important for it to be released from ontology per se. | |
From: Alain Badiou (Briefings on Existence [1998], 3) | |
A reaction: A startling proposal, for anyone who thought that ontology was First Philosophy. Badiou wants to hand ontology over to mathematicians, but I am unclear what remains for the philosophers to do. |
12324 | Consensus is the enemy of thought [Badiou] |
Full Idea: Consensus is the enemy of thought. | |
From: Alain Badiou (Briefings on Existence [1998], 2) | |
A reaction: A nice slogan for bringing Enlightenment optimists to a halt. I am struck. Do I allow my own thinking to always be diverted towards something which might result in a consensus? Do I actually (horror!) prefer consensus to truth? |
15375 | If terms change their designations in different states, they are functions from states to objects [Fitting] |
Full Idea: The common feature of every designating term is that designation may change from state to state - thus it can be formalized by a function from states to objects. | |
From: Melvin Fitting (Intensional Logic [2007], 3) | |
A reaction: Specifying the objects sounds OK, but specifying states sounds rather tough. |
15376 | Intensional logic adds a second type of quantification, over intensional objects, or individual concepts [Fitting] |
Full Idea: To first order modal logic (with quantification over objects) we can add a second kind of quantification, over intensions. An intensional object, or individual concept, will be modelled by a function from states to objects. | |
From: Melvin Fitting (Intensional Logic [2007], 3.3) |
15378 | Awareness logic adds the restriction of an awareness function to epistemic logic [Fitting] |
Full Idea: Awareness logic enriched Hintikka's epistemic models with an awareness function, mapping each state to the set of formulas we are aware of at that state. This reflects some bound on the resources we can bring to bear. | |
From: Melvin Fitting (Intensional Logic [2007], 3.6.1) | |
A reaction: [He cites Fagin and Halpern 1988 for this] |
15379 | Justication logics make explicit the reasons for mathematical truth in proofs [Fitting] |
Full Idea: In justification logics, the logics of knowledge are extended by making reasons explicit. A logic of proof terms was created, with a semantics. In this, mathematical truths are known for explicit reasons, and these provide a measure of complexity. | |
From: Melvin Fitting (Intensional Logic [2007], 3.6.1) |
12337 | There is 'transivity' iff membership ∈ also means inclusion ⊆ [Badiou] |
Full Idea: 'Transitivity' signifies that all of the elements of the set are also parts of the set. If you have α∈Β, you also have α⊆Β. This correlation of membership and inclusion gives a stability which is the sets' natural being. | |
From: Alain Badiou (Briefings on Existence [1998], 11) |
12321 | The axiom of choice must accept an indeterminate, indefinable, unconstructible set [Badiou] |
Full Idea: The axiom of choice actually amounts to admitting an absolutely indeterminate infinite set whose existence is asserted albeit remaining linguistically indefinable. On the other hand, as a process, it is unconstructible. | |
From: Alain Badiou (Briefings on Existence [1998], 2) | |
A reaction: If only constructible sets are admitted (see 'V = L') then there is a contradiction. |
12342 | Topos theory explains the plurality of possible logics [Badiou] |
Full Idea: Topos theory explains the plurality of possible logics. | |
From: Alain Badiou (Briefings on Existence [1998], 14) | |
A reaction: This will because logic will have a distinct theory within each 'topos'. |
11026 | Classical logic is deliberately extensional, in order to model mathematics [Fitting] |
Full Idea: Mathematics is typically extensional throughout (we write 3+2=2+3 despite the two terms having different meanings). ..Classical first-order logic is extensional by design since it primarily evolved to model the reasoning of mathematics. | |
From: Melvin Fitting (Intensional Logic [2007], §1) |
12341 | Logic is a mathematical account of a universe of relations [Badiou] |
Full Idea: Logic should first and foremost be a mathematical thought of what a universe of relations is. | |
From: Alain Badiou (Briefings on Existence [1998], 14) |
11028 | λ-abstraction disambiguates the scope of modal operators [Fitting] |
Full Idea: λ-abstraction can be used to abstract and disambiguate a predicate. De re is [λx◊P(x)](f) - f has the possible-P property - and de dicto is ◊[λxP(x)](f) - possibly f has the P-property. Also applies to □. | |
From: Melvin Fitting (Intensional Logic [2007], §3.3) | |
A reaction: Compare the Barcan formula. Originated with Church in the 1930s, and Carnap 1947, but revived by Stalnaker and Thomason 1968. Because it refers to the predicate, it has a role in intensional versions of logic, especially modal logic. |
9812 | In mathematics, if a problem can be formulated, it will eventually be solved [Badiou] |
Full Idea: Only in mathematics can one unequivocally maintain that if thought can formulate a problem, it can and will solve it, regardless of how long it takes. | |
From: Alain Badiou (Mathematics and Philosophy: grand and little [2004], p.17) | |
A reaction: I hope this includes proving the Continuum Hypothesis, and Goldbach's Conjecture. It doesn't seem quite true, but it shows why philosophers of a rationalist persuasion are drawn to mathematics. |
12334 | There is no single unified definition of number [Badiou] |
Full Idea: Apparently - and this is quite unlike old Greek times - there is no single unified definition of number. | |
From: Alain Badiou (Briefings on Existence [1998], 11) |
12335 | Numbers are for measuring and for calculating (and the two must be consistent) [Badiou] |
Full Idea: Number is an instance of measuring (distinguishing the more from the less, and calibrating data), ..and a figure for calculating (one counts with numbers), ..and it ought to be a figure of consistency (the compatibility of order and calculation). | |
From: Alain Badiou (Briefings on Existence [1998], 11) |
12333 | Each type of number has its own characteristic procedure of introduction [Badiou] |
Full Idea: There is a heterogeneity of introductory procedures of different classical number types: axiomatic for natural numbers, structural for ordinals, algebraic for negative and rational numbers, topological for reals, mainly geometric for complex numbers. | |
From: Alain Badiou (Briefings on Existence [1998], 11) |
12322 | Must we accept numbers as existing when they no longer consist of units? [Badiou] |
Full Idea: Do we have to confer existence on numbers whose principle is to no longer consist of units? | |
From: Alain Badiou (Briefings on Existence [1998], 2) | |
A reaction: This very nicely expresses what seems to me perhaps the most important question in the philosophy of mathematics. I am reluctant to accept such 'unitless' numbers, but I then feel hopelessly old-fashioned and naïve. What to do? |
9813 | Mathematics shows that thinking is not confined to the finite [Badiou] |
Full Idea: Mathematics teaches us that there is no reason whatsoever to confne thinking within the ambit of finitude. | |
From: Alain Badiou (Mathematics and Philosophy: grand and little [2004], p.19) | |
A reaction: This would perhaps make Cantor the greatest thinker who ever lived. It is an exhilarating idea, but we should ward the reader against romping of into unrestrained philosophical thought about infinities. You may be jumping without your Cantorian parachute. |
12327 | The undecidability of the Continuum Hypothesis may have ruined or fragmented set theory [Badiou] |
Full Idea: As we have known since Paul Cohen's theorem, the Continuum Hypothesis is intrinsically undecidable. Many believe Cohen's discovery has driven the set-theoretic project into ruin, or 'pluralized' what was once presented as a unified construct. | |
From: Alain Badiou (Briefings on Existence [1998], 6) | |
A reaction: Badiou thinks the theorem completes set theory, by (roughly) finalising its map. |
12329 | If mathematics is a logic of the possible, then questions of existence are not intrinsic to it [Badiou] |
Full Idea: If mathematics is a logic of the possible, then questions of existence are not intrinsic to it (as they are for the Platonist). | |
From: Alain Badiou (Briefings on Existence [1998], 7) | |
A reaction: See also Idea 12328. I file this to connect it with Hellman's modal (and nominalist) version of structuralism. Could it be that mathematics and modal logic are identical? |
12328 | Platonists like axioms and decisions, Aristotelians like definitions, possibilities and logic [Badiou] |
Full Idea: A Platonist's interest focuses on axioms in which the decision of thought is played out, where an Aristotelian or Leibnizian interest focuses on definitions laying out the representation of possibilities (...and the essence of mathematics is logic). | |
From: Alain Badiou (Briefings on Existence [1998], 7) | |
A reaction: See Idea 12323 for the significance of the Platonist approach. So logicism is an Aristotelian project? Frege is not a true platonist? I like the notion of 'the representation of possibilities', so will vote for the Aristotelians, against Badiou. |
12331 | Logic is definitional, but real mathematics is axiomatic [Badiou] |
Full Idea: Logic is definitional, whereas real mathematics is axiomatic. | |
From: Alain Badiou (Briefings on Existence [1998], 10) |
9809 | Mathematics inscribes being as such [Badiou] |
Full Idea: Mathematics inscribes being as such. | |
From: Alain Badiou (Mathematics and Philosophy: grand and little [2004], p.12) | |
A reaction: I don't pretend to understand that, but there is something about the purity and certainty of mathematics that makes us feel we are grappling with the core of existence. Perhaps. The same might be said of stubbing your toe on a bedpost. |
12340 | There is no Being as a whole, because there is no set of all sets [Badiou] |
Full Idea: The fundamental theorem that 'there does not exist a set of all sets' designates the inexistence of Being as a whole. ...A crucial consequence of this property is that any ontological investigation is irremediably local. | |
From: Alain Badiou (Briefings on Existence [1998], 14) | |
A reaction: The second thought pushes Badiou into Topos Theory, where the real numbers (for example) have a separate theory in each 'topos'. |
12323 | Existence is Being itself, but only as our thought decides it [Badiou] |
Full Idea: Existence is precisely Being itself in as much as thought decides it. And that decision orients thought essentially. ...It is when you decide upon what exists that you bind your thought to Being. | |
From: Alain Badiou (Briefings on Existence [1998], 2) | |
A reaction: [2nd half p.57] Helpful for us non-Heideggerians to see what is going on. Does this mean that Being is Kant's noumenon? |
12332 | The modern view of Being comes when we reject numbers as merely successions of One [Badiou] |
Full Idea: The saturation and collapse of the Euclidean idea of the being of number as One's procession signs the entry of the thought of Being into modern times. | |
From: Alain Badiou (Briefings on Existence [1998], 11) | |
A reaction: That is, by allowing that not all numbers are built of units, numbers expand widely enough to embrace everything we think of as Being. The landmark event is the acceptance of the infinite as a number. |
12326 | The primitive name of Being is the empty set; in a sense, only the empty set 'is' [Badiou] |
Full Idea: In Set Theory, the primitive name of Being is the void, the empty set. The whole hierarchy takes root in it. In a certain sense, it alone 'is'. | |
From: Alain Badiou (Briefings on Existence [1998], 6) | |
A reaction: This is the key to Badiou's view that ontology is mathematics. David Lewis pursued interesting enquiries in this area. |
9811 | It is of the essence of being to appear [Badiou] |
Full Idea: It is of the essence of being to appear. | |
From: Alain Badiou (Mathematics and Philosophy: grand and little [2004], p.16) | |
A reaction: Nice slogan. In my humble opinion 'continental' philosophy is well worth reading because, despite the fluffy rhetoric and the shameless egotism and the desire to shock the bourgeoisie, they occasionally make wonderfully thought-provoking remarks. |
12320 | Ontology is (and always has been) Cantorian mathematics [Badiou] |
Full Idea: Enlightened by the Cantorian grounding of mathematics, we can assert ontology to be nothing other than mathematics itself. This has been the case ever since its Greek origin. | |
From: Alain Badiou (Briefings on Existence [1998], 1) | |
A reaction: There seems to be quite a strong feeling among mathematicians that new 'realms of being' are emerging from their researches. Only a Platonist, of course, is likely to find this idea sympathetic. |
15377 | Definite descriptions pick out different objects in different possible worlds [Fitting] |
Full Idea: Definite descriptions pick out different objects in different possible worlds quite naturally. | |
From: Melvin Fitting (Intensional Logic [2007], 3.4) | |
A reaction: A definite description can pick out the same object in another possible world, or a very similar one, or an object which has almost nothing in common with the others. |
3102 | Why don't we experience or remember going to sleep at night? [Magee] |
Full Idea: As a child it was incomprehensible to me that I did not experience going to sleep, and never remembered it. When my sister said 'Nobody remembers that', I just thought 'How does she know?' | |
From: Bryan Magee (Confessions of a Philosopher [1997], Ch.I) | |
A reaction: This is actually evidence for something - that we do not have some sort of personal identity which is separate from consciousness, so that "I am conscious" would literally mean that an item has a property, which it can lose. |
12338 | We must either assert or deny any single predicate of any single subject [Badiou] |
Full Idea: There can be nothing intermediate to an assertion and a denial. We must either assert or deny any single predicate of any single subject. | |
From: Alain Badiou (Briefings on Existence [1998], 1011b24) | |
A reaction: The first sentence seems to be bivalence, and the second sentence excluded middle. |
9814 | All great poetry is engaged in rivalry with mathematics [Badiou] |
Full Idea: Like every great poet, Mallarmé was engaged in a tacit rivalry with mathematics. | |
From: Alain Badiou (Mathematics and Philosophy: grand and little [2004], p.20) | |
A reaction: I love these French pronouncements! Would Mallarmé have agreed? If poetry and mathematics are the poles, where is philosophy to be found? |
12316 | For Enlightenment philosophers, God was no longer involved in politics [Badiou] |
Full Idea: For the philosophers of the Enlightenment politics is strictly the affair of humankind, an immanent practice from which recourse to the All Mighty's providential organization had to be discarded. | |
From: Alain Badiou (Briefings on Existence [1998], Prol) |
12317 | The God of religion results from an encounter, not from a proof [Badiou] |
Full Idea: The God of metaphysics makes sense of existing according to a proof, while the God of religion makes sense of living according to an encounter | |
From: Alain Badiou (Briefings on Existence [1998], Prol) |