32 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. |
| 10061 | The If-thenist view only seems to work for the axiomatised portions of mathematics [Musgrave] |
| Full Idea: The If-thenist view seems to apply straightforwardly only to the axiomatised portions of mathematics. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: He cites Lakatos to show that cutting-edge mathematics is never axiomatised. One might reply that if the new mathematics is any good then it ought to be axiomatis-able (barring Gödelian problems). |
| 10065 | Perhaps If-thenism survives in mathematics if we stick to first-order logic [Musgrave] |
| Full Idea: If we identify logic with first-order logic, and mathematics with the collection of first-order theories, then maybe we can continue to maintain the If-thenist position. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: The problem is that If-thenism must rely on rules of inference. That seems to mean that what is needed is Soundness, rather than Completeness. That is, inference by the rules must work properly. |
| 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. |
| 10049 | Logical truths may contain non-logical notions, as in 'all men are men' [Musgrave] |
| Full Idea: Containing only logical notions is not a necessary condition for being a logical truth, since a logical truth such as 'all men are men' may contain non-logical notions such as 'men'. | |
| From: Alan Musgrave (Logicism Revisited [1977], §3) | |
| A reaction: [He attributes this point to Russell] Maybe it is only a logical truth in its general form, as ∀x(x=x). Of course not all 'banks' are banks. |
| 10050 | A statement is logically true if it comes out true in all interpretations in all (non-empty) domains [Musgrave] |
| Full Idea: The standard modern view of logical truth is that a statement is logically true if it comes out true in all interpretations in all (non-empty) domains. | |
| From: Alan Musgrave (Logicism Revisited [1977], §3) |
| 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. |
| 10058 | No two numbers having the same successor relies on the Axiom of Infinity [Musgrave] |
| Full Idea: The axiom of Peano which states that no two numbers have the same successor requires the Axiom of Infinity for its proof. | |
| From: Alan Musgrave (Logicism Revisited [1977], §4 n) | |
| A reaction: [He refers to Russell 1919:131-2] The Axiom of Infinity is controversial and non-logical. |
| 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. |
| 10062 | Formalism seems to exclude all creative, growing mathematics [Musgrave] |
| Full Idea: Formalism seems to exclude from consideration all creative, growing mathematics. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: [He cites Lakatos in support] I am not immediately clear why spotting the remote implications of a formal system should be uncreative. The greatest chess players are considered to be highly creative and imaginative. |
| 10063 | Formalism is a bulwark of logical positivism [Musgrave] |
| Full Idea: Formalism is a bulwark of logical positivist philosophy. | |
| From: Alan Musgrave (Logicism Revisited [1977], §5) | |
| A reaction: Presumably if you drain all the empirical content out of arithmetic and geometry, you are only left with the bare formal syntax, of symbols and rules. That seems to be as analytic as you can get. |
| 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. |
| 7647 | The imagination alone perceives all objects; it is the soul, playing all its roles [La Mettrie] |
| Full Idea: The imagination alone perceives; it forms an idea of all objects, with the words and figures that characterise them; thus the imagination is the soul, because it plays all its roles. | |
| From: Julien Offray de La Mettrie (Machine Man [1747], p.15) | |
| A reaction: This is not just a big claim for the importance of imagination, in strong opposition to Descartes's rather dismissive view (Idea 1399), but also appears to be the germ of an interesting theory about the nature of personal identity. |
| 7645 | When falling asleep, the soul becomes paralysed and weak, just like the body [La Mettrie] |
| Full Idea: The soul and body fall asleep together. The soul slowly becomes paralysed, together with all the body's muscles. They can no longer hold up the weight of the head, while the soul can no longer bear the burden of thought. | |
| From: Julien Offray de La Mettrie (Machine Man [1747], p.6) | |
| A reaction: A very nice observation, to place alongside other evidence such as drunkenness and blushing. Personally I find it hard to see why anyone ever believed dualism. You don't need modern brain scans and brain lesion research to see the problem. |
| 23225 | The soul's faculties depend on the brain, and are simply the brain's organisation [La Mettrie] |
| Full Idea: All the soul's faculties depend so much on the specific organisation of the brain and of the whole body that they are clearly nothing but that organisation. | |
| From: Julien Offray de La Mettrie (Machine Man [1747], p.26) | |
| A reaction: An interesting idea because it suggests that La Mettrie is a functionalist, rather than simply a reductive physicalist. |
| 7652 | Man is a machine, and there exists only one substance, diversely modified [La Mettrie] |
| Full Idea: Let us conclude boldly that man is a machine and that there is in the whole universe only one diversely modified substance. | |
| From: Julien Offray de La Mettrie (Machine Man [1747], p.39) | |
| A reaction: What courage it must have taken to write what now seems a perfectly acceptable and normal view. One day there should be a collective monument to Hobbes, Gassendi, Spinoza, La Mettrie and Hume, who thought so boldly. |
| 7650 | All thought is feeling, and rationality is the sensitive soul contemplating reasoning [La Mettrie] |
| Full Idea: Thought is only a capacity to feel, and the rational soul is only the sensitive soul applied to the contemplation of ideas and to reasoning. | |
| From: Julien Offray de La Mettrie (Machine Man [1747], p.33) | |
| A reaction: What a very nice idea. La Mettrie wants to bring us closer to animals. Because we can pursue a train of rational thought, it does not follow that we have a faculty called 'rationality'. A dog can follow a clever series of clues that lead to food. |
| 7651 | With wonderful new machines being made, a speaking machine no longer seems impossible [La Mettrie] |
| Full Idea: If wonderful machines like Huygens's planetary clock can be made, it would take even more cogs and springs to make a speaking machine, which can no longer be considered impossible, particularly at the hands of a new Prometheus. | |
| From: Julien Offray de La Mettrie (Machine Man [1747], p.34) | |
| A reaction: Compare Descartes in Idea 3614. The idea of artificial intelligence does not arise with the advent of computers; it follows naturally from the materialist view of the mind, along with a bit of ambition to build complex machines. |
| 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'. |
| 10060 | Logical positivists adopted an If-thenist version of logicism about numbers [Musgrave] |
| Full Idea: Logical positivists did not adopt old-style logicism, but rather logicism spiced with varying doses of If-thenism. | |
| From: Alan Musgrave (Logicism Revisited [1977], §4) | |
| A reaction: This refers to their account of mathematics as a set of purely logical truths, rather than being either empirical, or a priori synthetic. |
| 7648 | The sun and rain weren't made for us; they sometimes burn us, or spoil our seeds [La Mettrie] |
| Full Idea: The sun was not made in order to heat the earth and all its inhabitants - whom it sometimes burns - any more than the rain was created in order to grow seeds - which it often spoils. | |
| From: Julien Offray de La Mettrie (Machine Man [1747]) | |
| A reaction: This denial of Aristotelian (and divine) teleology is as much part of the movement against religion, as are concerns about natural evil, and about the weakness of arguments for God's existence. These facts were obvious long before La Mettrie. |
| 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? |
| 7646 | There is no abrupt transition from man to animal; only language has opened a gap [La Mettrie] |
| Full Idea: From animals to man there is no abrupt transition. What was man before he invented words and learnt languages? An animal of a particular species, with much less natural instinct than the others. | |
| From: Julien Offray de La Mettrie (Machine Man [1747], p.13) | |
| A reaction: This shows how strongly the evolutionary idea was in the air, a century before Darwin proposed a mechanism for it. This thought is the beginning of a very new view of man, and also of a very new view of animals. |
| 7649 | There is no clear idea of the soul, which should only refer to our thinking part [La Mettrie] |
| Full Idea: The soul is merely a vain term of which we have no idea and which a good mind should use only to refer to that part of us which thinks. | |
| From: Julien Offray de La Mettrie (Machine Man [1747]) | |
| A reaction: I have always found the concept of the soul particularly baffling. It seems that it is only believed in to make immortality possible, with no other purpose to the belief, let alone evidence. I suspect that Descartes agreed with La Mettrie on this. |