26 ideas
| 9921 | 'True' is only occasionally useful, as in 'everything Fermat believed was true' [Burgess/Rosen] |
| Full Idea: In the disquotational view of truth, what saves truth from being wholly redundant and so wholly useless, is mainly that it provides an ability to state generalisations like 'Everything Fermat believed was true'. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], I.A.2.c) | |
| A reaction: Sounds like the thin end of the wedge. Presumably we can infer that the first thing Fermat believed on his last Christmas Day was true. |
| 9924 | Modal logic gives an account of metalogical possibility, not metaphysical possibility [Burgess/Rosen] |
| Full Idea: If you want a logic of metaphysical possibility, the existing literature was originally developed to supply a logic of metalogical possibility, and still reflects its origins. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], II.B.3.b) | |
| A reaction: This is a warning shot (which I don't fully understand) to people like me, who were beginning to think they could fill their ontology with possibilia, which could then be incorporated into the wider account of logical thinking. Ah well... |
| 9933 | The paradoxes are only a problem for Frege; Cantor didn't assume every condition determines a set [Burgess/Rosen] |
| Full Idea: The paradoxes only seem to arise in connection with Frege's logical notion of extension or class, not Cantor's mathematical notion of set. Cantor never assumed that every condition determines a set. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], III.C.1.b) | |
| A reaction: This makes the whole issue a parochial episode in the history of philosophy, not a central question. Cantor favoured some sort of abstractionism (see Kit Fine on the subject). |
| 9928 | Mereology implies that acceptance of entities entails acceptance of conglomerates [Burgess/Rosen] |
| Full Idea: Mereology has ontological implications. The acceptance of some initial entities involves the acceptance of many further entities, arbitrary wholes having the entities as parts. It must accept conglomerates. Geometric points imply geometric regions. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], II.C.1.b) | |
| A reaction: Presumably without the wholes being entailed by the parts, there is no subject called 'mereology'. But if the conglomeration is unrestricted, there is not much left to be said. 'Restricted' composition (by nature?) sounds a nice line. |
| 9926 | A relation is either a set of sets of sets, or a set of sets [Burgess/Rosen] |
| Full Idea: While in general a relation is taken to be a set of ordered pairs <u, v> = {{u}, {u, v}}, and hence a set of sets of sets, in special cases a relation can be represented by a set of sets. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], II.C.1.a) | |
| A reaction: [See book for their examples, which are <, symmetric, and arbitrary] The fact that a relation (or anything else) can be represented in a certain way should never ever be taken to mean that you now know what the thing IS. |
| 9932 | The paradoxes no longer seem crucial in critiques of set theory [Burgess/Rosen] |
| Full Idea: Recent commentators have de-emphasised the set paradoxes because they play no prominent part in motivating the most articulate and active opponents of set theory, such as Kronecker (constructivism) or Brouwer (intuitionism), or Weyl (predicativism). | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], III.C.1.b) | |
| A reaction: This seems to be a sad illustration of the way most analytical philosophers have to limp along behind the logicians and mathematicians, arguing furiously about problems that have largely been abandoned. |
| 9923 | We should talk about possible existence, rather than actual existence, of numbers [Burgess/Rosen] |
| Full Idea: The modal strategy for numbers is to replace assumptions about the actual existence of numbers by assumptions about the possible existence of numbers | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], II.B.3.a) | |
| A reaction: This seems to be quite a good way of dealing with very large numbers and infinities. It is not clear whether 5 is so regularly actualised that we must consider it as permanent, or whether it is just a prominent permanent possibility. |
| 9925 | Structuralism and nominalism are normally rivals, but might work together [Burgess/Rosen] |
| Full Idea: Usually structuralism and nominalism are considered rivals. But structuralism can also be the first step in a strategy of nominalist reconstrual or paraphrase. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], II.C.0) | |
| A reaction: Hellman and later Chihara seem to be the main proponents of nominalist structuralism. My sympathies lie with this strategy. Are there objects at the nodes of the structure, or is the structure itself platonic? Mill offers a route. |
| 9934 | Number words became nouns around the time of Plato [Burgess/Rosen] |
| Full Idea: The transition from using number words purely as adjectives to using them extensively as nouns has been traced to 'around the time of Plato'. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], III.C.2.a) | |
| A reaction: [The cite Kneale and Kneale VI,§2 for this] It is just too tempting to think that in fact Plato (and early Platonists) were totally responsible for this shift, since the whole reification of numbers seems to be inherently platonist. |
| 9918 | Abstract/concrete is a distinction of kind, not degree [Burgess/Rosen] |
| Full Idea: The distinction of abstract and concrete is one of kind and not degree. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], I.A.1.a) | |
| A reaction: I think I must agree with this. If there is a borderline, it would be in particulars that seem to have an abstract aspect to them. A horse involves the abstraction of being a horse, and it involves be one horse. |
| 9929 | Much of what science says about concrete entities is 'abstraction-laden' [Burgess/Rosen] |
| Full Idea: Much of what science says about concrete entities is 'abstraction-laden'. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], III.A.1.d) | |
| A reaction: Not just science. In ordinary conversation we continually refer to particulars using so-called 'universal' predicates and object-terms, which are presumably abstractions. 'I've just seen an elephant'. |
| 9927 | Mathematics has ascended to higher and higher levels of abstraction [Burgess/Rosen] |
| Full Idea: In mathematics, since the beginning of the nineteenth century, there has been an ascent to higher and higher levels of abstraction. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], II.C.1.b) | |
| A reaction: I am interested in clarifying what this means, which might involve the common sense and psychological view of the matter, as well as some sort of formal definition in terms of equivalence (or whatever). |
| 9930 | Abstraction is on a scale, of sets, to attributes, to type-formulas, to token-formulas [Burgess/Rosen] |
| Full Idea: There is a scale of abstractness that leads downwards from sets through attributes to formulas as abstract types and on to formulas as abstract tokens. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], III.B.2.c) | |
| A reaction: Presumably the 'abstract tokens' at the bottom must have some interpretation, to support the system. Presumably one can keep going upwards, through sets of sets of sets. |
| 16755 | The possible Aristotelian view that forms are real and active principles is clearly wrong [Fine,K, by Pasnau] |
| Full Idea: Aristotle seems to have a possible basis for the belief [in individual forms], namely that forms are real and active principles in the world, which is denied by any right-minded modern. | |
| From: report of Kit Fine (A Puzzle Concerning Matter and Form [1994], p.19) by Robert Pasnau - Metaphysical Themes 1274-1671 24.3 n8 | |
| A reaction: Pasnau says this is the view of forms promoted by the scholastics, whereas Aristotle's own view should be understood as 'metaphysical'. |
| 12184 | Logical necessity overrules all other necessities [McFetridge] |
| Full Idea: If it is logically necessary that if p then q, then there is no other sense of 'necessary' in which it is not necessary that if p then q. | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §1) | |
| A reaction: The thesis which McFetridge proposes to defend. The obvious rival would be metaphysical necessity, and the rival claim would presumably be that things are only logically necessary if that is entailed by a metaphysical necessity. Metaphysics drives logic. |
| 15083 | The fundamental case of logical necessity is the valid conclusion of an inference [McFetridge, by Hale] |
| Full Idea: McFetridge's conception of logical necessity is one which sees the concept as receiving its fundamental exemplification in the connection between the premiss and conclusion of a deductively valid inference. | |
| From: report of Ian McFetridge (Logical Necessity: Some Issues [1986]) by Bob Hale - Absolute Necessities 2 | |
| A reaction: This would mean that p could be logically necessary but false (if it was a valid argument from false premisses). What if it was a valid inference in a dodgy logical system (including 'tonk', for example)? |
| 15084 | In the McFetridge view, logical necessity means a consequent must be true if the antecedent is [McFetridge, by Hale] |
| Full Idea: McFetridge's view proves that if the conditional corresponding to a valid inference is logically necessary, then there is no sense in which it is possible that its antecedent be true but its consequent false. ..This result generalises to any statement. | |
| From: report of Ian McFetridge (Logical Necessity: Some Issues [1986]) by Bob Hale - Absolute Necessities 2 | |
| A reaction: I am becoming puzzled by Hale's assertion that logical necessity is 'absolute', while resting his case on a conditional. Are we interested in the necessity of the inference, or the necessity of the consequent? |
| 12180 | Logical necessity requires that a valid argument be necessary [McFetridge] |
| Full Idea: There will be a legitimate notion of 'logical' necessity only if there is a notion of necessity which attaches to the claim, concerning a deductively valid argument, that if the premisses are true then so is the conclusion. | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §1) | |
| A reaction: He quotes Aristotle's Idea 11148 in support. Is this resting a stronger idea on a weaker one? Or is it the wrong way round? We endorse validity because we see the necessity; we don't endorse necessity because we see 'validity'. |
| 12181 | Traditionally, logical necessity is the strongest, and entails any other necessities [McFetridge] |
| Full Idea: The traditional crucial assumption is that logical necessity is the strongest notion of necessity. If it is logically necessary that p, then it is necessary that p in any other use of the notion of necessity there may be (physically, practically etc.). | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §1) | |
| A reaction: Sounds right. We might say it is physically necessary simply because it is logically necessary, and even that it is metaphysically necessary because it is logically necessary (required by logic). Logical possibility is hence the weakest kind? |
| 12183 | It is only logical necessity if there is absolutely no sense in which it could be false [McFetridge] |
| Full Idea: Is there any sense in which, despite an ascription of necessity to p, it is held that not-p is possible? If there is, then the original claim then it was necessary is not a claim of 'logical' necessity (which is the strongest necessity). | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §1) | |
| A reaction: See Idea 12181, which leads up to this proposed "test" for logical necessity. McFetridge has already put epistemic ('for all I know') possibility to one side. □p→¬◊¬p is the standard reading of necessity. His word 'sense' bears the burden. |
| 12192 | The mark of logical necessity is deduction from any suppositions whatever [McFetridge] |
| Full Idea: The manifestation of the belief that a mode of inference is logically necessarily truth-preserving is the preparedness to employ that mode of inference in reasoning from any set of suppositions whatsoever. | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §4) | |
| A reaction: He rests this on the idea of 'cotenability' of the two sides of a counterfactual (in Mill, Goodman and Lewis). There seems, at first blush, to be a problem of the relevance of the presuppositions. |
| 12182 | We assert epistemic possibility without commitment to logical possibility [McFetridge] |
| Full Idea: Time- and person-relative epistemic possibility can be asserted even when logical possibility cannot, such as undecided mathematical propositions. 'It may be that p' just comes to 'For all I know, not-p'. | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §1) | |
| A reaction: If it is possible 'for all I know', then it could be actual for all I know, and if we accept that it might be actual, we could hardly deny that it is logically possible. Logical and epistemic possibilities of mathematical p stand or fall together. |
| 12187 | Objectual modal realists believe in possible worlds; non-objectual ones rest it on the actual world [McFetridge] |
| Full Idea: The 'objectual modal realist' holds that what makes modal beliefs true are certain modal objects, typically 'possible worlds'. ..The 'non-objectual modal realist' says modal judgements are made true by how things stand with respect to this world. | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §2) | |
| A reaction: I am an enthusiastic 'non-objectual modal realist'. I accept the argument that real possible worlds have no relevance to the actual world, and explain nothing (see Jubien). The possibilities reside in the 'powers' of this world. See Molnar on powers. |
| 12186 | Modal realists hold that necessities and possibilities are part of the totality of facts [McFetridge] |
| Full Idea: The 'modal realist' holds that part of the totality of what is the case, the totality of facts, are such things as that certain events could have happened, certain propositions are necessarily true, if this happened then that would have been the case. | |
| From: Ian McFetridge (Logical Necessity: Some Issues [1986], §2) | |
| A reaction: I am an enthusiastic modal realist. If the aim of philosophy is 'to understand' (and I take that to be the master idea of the subject) then no understanding is possible which excludes the possibilities and necessities in things. |
| 9919 | The old debate classified representations as abstract, not entities [Burgess/Rosen] |
| Full Idea: The original debate was over abstract ideas; thus it was mental (or linguistic) representations that were classified as abstract or otherwise, and not the entities represented. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], I.A.1.b) | |
| A reaction: This seems to beg the question of whether there are any such entities. It is equally plausible to talk of the entities that are 'constructed', rather than 'represented'. |
| 9922 | If space is really just a force-field, then it is a physical entity [Burgess/Rosen] |
| Full Idea: According to many philosophical commentators, a force-field must be considered to be a physical entity, and as the distinction between space and the force-field may be considered to be merely verbal, space itself may be considered to be a physical entity. | |
| From: JP Burgess / G Rosen (A Subject with No Object [1997], II.A.1) | |
| A reaction: The ontology becomes a bit odd if we cheerfully accept that space is physical, but then we can't give the same account of time. I'm not sure how time could be physical. What's it made of? |