41 ideas
| 3358 | Metaphysics focuses on Platonism, essentialism, materialism and anti-realism [Benardete,JA] |
| Full Idea: In contemporary metaphysics the major areas of discussion are Platonism, essentialism, materialism and anti-realism. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], After) |
| 3312 | There are the 'is' of predication (a function), the 'is' of identity (equals), and the 'is' of existence (quantifier) [Benardete,JA] |
| Full Idea: At least since Russell, one has routinely distinguished between the 'is' of predication ('Socrates is wise', Fx), the 'is' of identity ('Morning Star is Evening Star', =), and the 'is' of existence ('the cat is under the bed', Ex). | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 7) | |
| A reaction: This seems horribly nitpicking to many people, but I love it - because it is just true, and it is a truth right at the basis of the confusions in our talk. Analytic philosophy forever! [P.S. 'Tiddles is a cat' - the 'is' membership] |
| 3352 | Analytical philosophy analyses separate concepts successfully, but lacks a synoptic vision of the results [Benardete,JA] |
| Full Idea: Analytical philosophy excels in the piecemeal analysis of causation, perception, knowledge and so on, but there is a striking poverty of any synoptic vision of these independent studies. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.22) |
| 3329 | Presumably the statements of science are true, but should they be taken literally or not? [Benardete,JA] |
| Full Idea: As our bible, the Book of Science is presumed to contain only true sentences, but it is less clear how they are to be construed, which literally and which non-literally. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.13) |
| 18806 | Frege thought traditional categories had psychological and linguistic impurities [Frege, by Rumfitt] |
| Full Idea: Frege rejected the traditional categories as importing psychological and linguistic impurities into logic. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by Ian Rumfitt - The Boundary Stones of Thought 1.2 | |
| A reaction: Resisting such impurities is the main motivation for making logic entirely symbolic, but it doesn't follow that the traditional categories have to be dropped. |
| 3326 | Set theory attempts to reduce the 'is' of predication to mathematics [Benardete,JA] |
| Full Idea: Set theory offers the promise of a complete mathematization of the 'is' of predication. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.13) |
| 3327 | The set of Greeks is included in the set of men, but isn't a member of it [Benardete,JA] |
| Full Idea: Set inclusion is sharply distinguished from set membership (as the set of Greeks is found to be included in, but not a member of, the set of men). | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.13) |
| 3335 | The standard Z-F Intuition version of set theory has about ten agreed axioms [Benardete,JA, by PG] |
| Full Idea: Zermelo proposed seven axioms for set theory, with Fraenkel adding others, to produce the standard Z-F Intuition. | |
| From: report of José A. Benardete (Metaphysics: the logical approach [1989], Ch.17) by PG - Db (ideas) |
| 8490 | First-level functions have objects as arguments; second-level functions take functions as arguments [Frege] |
| Full Idea: Just as functions are fundamentally different from objects, so also functions whose arguments are and must be functions are fundamentally different from functions whose arguments are objects. The latter are first-level, the former second-level, functions. | |
| From: Gottlob Frege (Function and Concept [1891], p.38) | |
| A reaction: In 1884 he called it 'second-order'. This is the standard distinction between first- and second-order logic. The first quantifies over objects, the second over intensional entities such as properties and propositions. |
| 8492 | Relations are functions with two arguments [Frege] |
| Full Idea: Functions of one argument are concepts; functions of two arguments are relations. | |
| From: Gottlob Frege (Function and Concept [1891], p.39) | |
| A reaction: Nowadays we would say 'two or more'. Another interesting move in the aim of analytic philosophy to reduce the puzzling features of the world to mathematical logic. There is, of course, rather more to some relations than being two-argument functions. |
| 3332 | Greeks saw the science of proportion as the link between geometry and arithmetic [Benardete,JA] |
| Full Idea: The Greeks saw the independent science of proportion as the link between geometry and arithmetic. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.15) |
| 3330 | Negatives, rationals, irrationals and imaginaries are all postulated to solve baffling equations [Benardete,JA] |
| Full Idea: The Negative numbers are postulated (magic word) to solve x=5-8, Rationals postulated to solve 2x=3, Irrationals for x-squared=2, and Imaginaries for x-squared=-1. (…and Zero for x=5-5) …and x/0 remains eternally open. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.14) |
| 3337 | Natural numbers are seen in terms of either their ordinality (Peano), or cardinality (set theory) [Benardete,JA] |
| Full Idea: One approaches the natural numbers in terms of either their ordinality (Peano), or cardinality (set theory). | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.17) |
| 18085 | Values that approach zero, becoming less than any quantity, are 'infinitesimals' [Cauchy] |
| Full Idea: When the successive absolute values of a variable decrease indefinitely in such a way as to become less than any given quantity, that variable becomes what is called an 'infinitesimal'. Such a variable has zero as its limit. | |
| From: Augustin-Louis Cauchy (Cours d'Analyse [1821], p.19), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.4 | |
| A reaction: The creator of the important idea of the limit still talked in terms of infinitesimals. In the next generation the limit took over completely. |
| 18084 | When successive variable values approach a fixed value, that is its 'limit' [Cauchy] |
| Full Idea: When the values successively attributed to the same variable approach indefinitely a fixed value, eventually differing from it by as little as one could wish, that fixed value is called the 'limit' of all the others. | |
| From: Augustin-Louis Cauchy (Cours d'Analyse [1821], p.19), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.4 | |
| A reaction: This seems to be a highly significan proposal, because you can now treat that limit as a number, and adds things to it. It opens the door to Cantor's infinities. Is the 'limit' just a fiction? |
| 8487 | Arithmetic is a development of logic, so arithmetical symbolism must expand into logical symbolism [Frege] |
| Full Idea: I am of the opinion that arithmetic is a further development of logic, which leads to the requirement that the symbolic language of arithmetic must be expanded into a logical symbolism. | |
| From: Gottlob Frege (Function and Concept [1891], p.30) | |
| A reaction: This may the the one key idea at the heart of modern analytic philosophy (even though logicism may be a total mistake!). Logic and arithmetical foundations become the master of ontology, instead of the servant. The jury is out on the whole enterprise. |
| 18899 | Frege takes the existence of horses to be part of their concept [Frege, by Sommers] |
| Full Idea: Frege regarded the existence of horses as a property of the concept 'horse'. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by Fred Sommers - Intellectual Autobiography 'Realism' |
| 3310 | If slowness is a property of walking rather than the walker, we must allow that events exist [Benardete,JA] |
| Full Idea: Once we conceded that Tom can walk slowly or quickly, and that the slowness and quickness is a property of the walking and not of Tom, we can hardly refrain from quantifying over events (such as 'a walking') in our ontology. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 6) |
| 12793 | Early pre-Socratics had a mass-noun ontology, which was replaced by count-nouns [Benardete,JA] |
| Full Idea: With their 'mass-noun' ontologies, the early pre-Socratics were blind to plurality ...but the count-noun ontologists came to dominate the field forever after. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 6) | |
| A reaction: The mass-nouns are such things as earth, air, fire and water. This is a very interesting historical observation (cited by Laycock). Our obsession with identity seems tied to formal logic. There is a whole other worldview waiting out there. |
| 4028 | Frege allows either too few properties (as extensions) or too many (as predicates) [Mellor/Oliver on Frege] |
| Full Idea: Frege's theory of properties (which he calls 'concepts') yields too few properties, by identifying coextensive properties, and also too many, by letting every predicate express a property. | |
| From: comment on Gottlob Frege (Function and Concept [1891]) by DH Mellor / A Oliver - Introduction to 'Properties' §2 | |
| A reaction: Seems right; one extension may have two properties (have heart/kidneys), two predicates might express the same property. 'Cutting nature at the joints' covers properties as well as objects. |
| 3353 | If there is no causal interaction with transcendent Platonic objects, how can you learn about them? [Benardete,JA] |
| Full Idea: How can you learn of the existence of transcendent Platonic objects if there is no causal interaction with them? | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.22) |
| 8489 | The concept 'object' is too simple for analysis; unlike a function, it is an expression with no empty place [Frege] |
| Full Idea: I regard a regular definition of 'object' as impossible, since it is too simple to admit of logical analysis. Briefly: an object is anything that is not a function, so that an expression for it does not contain any empty place. | |
| From: Gottlob Frege (Function and Concept [1891], p.32) | |
| A reaction: Here is the core of the programme for deriving our ontology from our logic and language, followed through by Russell and Quine. Once we extend objects beyond the physical, it becomes incredibly hard to individuate them. |
| 3304 | Why should packed-together particles be a thing (Mt Everest), but not scattered ones? [Benardete,JA] |
| Full Idea: Why suppose these particles packed together constitute a macro-entity (namely, Mt Everest), whereas those, of equal number, scattered around, fail to add up to anything beyond themselves? | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 2) |
| 3350 | Could a horse lose the essential property of being a horse, and yet continue to exist? [Benardete,JA] |
| Full Idea: Is being a horse an essential property of a horse? Can we so much as conceive the abstract possibility of a horse's ceasing to be a horse even while continuing to exist? | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.20) |
| 3309 | If a soldier continues to exist after serving as a soldier, does the wind cease to exist after it ceases to blow? [Benardete,JA] |
| Full Idea: If a soldier need not cease to exist merely because he ceases to be a soldier, there is room to doubt that the wind ceases to exist when it ceases to be a wind. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 6) |
| 3351 | One can step into the same river twice, but not into the same water [Benardete,JA] |
| Full Idea: One can step into the same river twice, but one must not expect to step into the same water. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.21) |
| 3323 | Maybe self-identity isn't existence, if Pegasus can be self-identical but non-existent [Benardete,JA] |
| Full Idea: 'Existence' can't be glossed as self-identical (critics say) because Pegasus, even while being self-identical, fails to exist. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.11) |
| 3314 | Absolutists might accept that to exist is relative, but relative to what? How about relative to itself? [Benardete,JA] |
| Full Idea: With the thesis that to be as such is to be relative, the absolutist may be found to concur, but the issue turns on what it might be that a thing is supposed to be relative to. Why not itself? | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 8) |
| 3306 | The clearest a priori knowledge is proving non-existence through contradiction [Benardete,JA] |
| Full Idea: One proves non-existence (e.g. of round squares) by using logic to derive a contradiction from the concept; it is precisely here, in such proofs, that we find the clearest example of a priori knowledge. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 4) |
| 3341 | Logical positivism amounts to no more than 'there is no synthetic a priori' [Benardete,JA] |
| Full Idea: Logical positivism has been concisely summarised as 'there is no synthetic a priori'. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.18) |
| 3344 | Assertions about existence beyond experience can only be a priori synthetic [Benardete,JA] |
| Full Idea: No one thinks that the proposition that something exists that transcends all possible experience harbours a logical inconsistency. Its denial cannot therefore be an analytic proposition, so it must be synthetic, though only knowable on a priori grounds. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.18) |
| 3349 | If we know truths about prime numbers, we seem to have synthetic a priori knowledge of Platonic objects [Benardete,JA] |
| Full Idea: Assume that we know to be true propositions of the form 'There are exactly x prime numbers between y and z', and synthetic a priori truths about Platonic objects are delivered to us on a silver platter. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.18) |
| 3345 | Appeals to intuition seem to imply synthetic a priori knowledge [Benardete,JA] |
| Full Idea: Appeals to intuition - no matter how informal - can hardly fail to smack of the synthetic a priori. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.18) |
| 9947 | Concepts are the ontological counterparts of predicative expressions [Frege, by George/Velleman] |
| Full Idea: Concepts, for Frege, are the ontological counterparts of predicative expressions. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2 | |
| A reaction: That sounds awfully like what many philosophers call 'universals'. Frege, as a platonist (at least about numbers), I would take to be in sympathy with that. At least we can say that concepts seem to be properties. |
| 10319 | An assertion about the concept 'horse' must indirectly speak of an object [Frege, by Hale] |
| Full Idea: Frege had a notorious difficulty over the concept 'horse', when he suggests that if we wish to assert something about a concept, we are obliged to proceed indirectly by speaking of an object that represents it. | |
| From: report of Gottlob Frege (Function and Concept [1891], Ch.2.II) by Bob Hale - Abstract Objects | |
| A reaction: This sounds like the thin end of a wedge. The great champion of objects is forced to accept them here as a façon de parler, when elsewhere they have ontological status. |
| 8488 | A concept is a function whose value is always a truth-value [Frege] |
| Full Idea: A concept in logic is closely connected with what we call a function. Indeed, we may say at once: a concept is a function whose value is always a truth-value. ..I give the name 'function' to what is meant by the 'unsaturated' part. | |
| From: Gottlob Frege (Function and Concept [1891], p.30) | |
| A reaction: So a function becomes a concept when the variable takes a value. Problems arise when the value is vague, or the truth-value is indeterminable. |
| 9948 | Unlike objects, concepts are inherently incomplete [Frege, by George/Velleman] |
| Full Idea: For Frege, concepts differ from objects in being inherently incomplete in nature. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2 | |
| A reaction: This is because they are 'unsaturated', needing a quantified variable to complete the sentence. This could be a pointer towards Quine's view of properties, as simply an intrinsic feature of predication about objects, with no separate identity. |
| 4972 | I may regard a thought about Phosphorus as true, and the same thought about Hesperus as false [Frege] |
| Full Idea: From sameness of meaning there does not follow sameness of thought expressed. A fact about the Morning Star may express something different from a fact about the Evening Star, as someone may regard one as true and the other false. | |
| From: Gottlob Frege (Function and Concept [1891], p.14) | |
| A reaction: This all gets clearer if we distinguish internalist and externalist theories of content. Why take sides on this? Why not just ask 'what is in the speaker's head?', 'what does the sentence mean in the community?', and 'what is the corresponding situation?' |
| 3334 | Rationalists see points as fundamental, but empiricists prefer regions [Benardete,JA] |
| Full Idea: Rationalists have been happier with an ontology of points, and empiricists with an ontology of regions. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch.16) |
| 3308 | In the ontological argument a full understanding of the concept of God implies a contradiction in 'There is no God' [Benardete,JA] |
| Full Idea: In the ontological argument a deep enough understanding of the very concept of God allows one to derive by logic a contradiction from the statement 'There is no God'. | |
| From: José A. Benardete (Metaphysics: the logical approach [1989], Ch. 4) |
| 8491 | The Ontological Argument fallaciously treats existence as a first-level concept [Frege] |
| Full Idea: The ontological proof of God's existence suffers from the fallacy of treating existence as a first-level concept. | |
| From: Gottlob Frege (Function and Concept [1891], p.38 n) | |
| A reaction: [See Idea 8490 for first- and second-order functions] This is usually summarised as the idea that existence is a quantifier rather than a predicate. |