32 ideas
19695 | The devil was wise as an angel, and lost no knowledge when he rebelled [Whitcomb] |
Full Idea: The devil is evil but nonetheless wise; he was a wise angel, and through no loss of knowledge, but, rather, through some sort of affective restructuring tried and failed to take over the throne. | |
From: Dennis Whitcomb (Wisdom [2011], 'Argument') | |
A reaction: ['affective restructuring' indeed! philosophers- don't you love 'em?] To fail at something you try to do suggests a flaw in the wisdom. And the new regime the devil wished to introduce doesn't look like a wise regime. Not convinced. |
9570 | In Field's Platonist view, set theory is false because it asserts existence for non-existent things [Field,H, by Chihara] |
Full Idea: Field commits himself to a Platonic view of mathematics. The theorems of set theory are held to imply or presuppose the existence of things that don't in fact exist. That is why he believes that these theorems are false. | |
From: report of Hartry Field (Science without Numbers [1980]) by Charles Chihara - A Structural Account of Mathematics 11.1 | |
A reaction: I am sympathetic to Field, but this sounds wrong. A response that looks appealing is that maths is hypothetical ('if-thenism') - the truth is in the logical consequences, not in the ontological presuppositions. |
10260 | Logical consequence is defined by the impossibility of P and ¬q [Field,H, by Shapiro] |
Full Idea: Field defines logical consequence by taking the notion of 'logical possibility' as primitive. Hence q is a consequence of P if the conjunction of the items in P with the negation of q is not possible. | |
From: report of Hartry Field (Science without Numbers [1980]) by Stewart Shapiro - Philosophy of Mathematics 7.2 | |
A reaction: The question would then be whether it is plausible to take logical possibility as primitive. Presumably only intuition could support it. But then intuition will equally support natural and metaphysical possibilities. |
15091 | Restrict 'logical truth' to formal logic, rather than including analytic and metaphysical truths [Shoemaker] |
Full Idea: I favour restricting the term 'logical truth' to what logicians would count as such, excluding both analytic truths like 'Bachelors are unmarried' and Kripkean necessities like 'Gold is an element'. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], I) | |
A reaction: I agree. There is a tendency to splash the phrases 'logical truth' and 'logical necessity around in vague ways. I take them to strictly arise out of the requirements of formal systems of logic. |
8958 | In Field's version of science, space-time points replace real numbers [Field,H, by Szabó] |
Full Idea: Field's nominalist version of science develops a version of Newtonian gravitational theory, where no quantifiers range over mathematical entities, and space-time points and regions play the role of surrogates for real numbers. | |
From: report of Hartry Field (Science without Numbers [1980]) by Zoltán Gendler Szabó - Nominalism 5.1 | |
A reaction: This seems to be a very artificial contrivance, but Field has launched a programme for rewriting science so that numbers can be omitted. All of this is Field's rebellion against the Indispensability Argument for mathematics. I sympathise. |
18221 | 'Metric' axioms uses functions, points and numbers; 'synthetic' axioms give facts about space [Field,H] |
Full Idea: There are two approaches to axiomatising geometry. The 'metric' approach uses a function which maps a pair of points into the real numbers. The 'synthetic' approach is that of Euclid and Hilbert, which does without real numbers and functions. | |
From: Hartry Field (Science without Numbers [1980], 5) |
8757 | The Indispensability Argument is the only serious ground for the existence of mathematical entities [Field,H] |
Full Idea: There is one and only one serious argument for the existence of mathematical entities, and that is the Indispensability Argument of Putnam and Quine. | |
From: Hartry Field (Science without Numbers [1980], p.5), quoted by Stewart Shapiro - Thinking About Mathematics 9.1 | |
A reaction: Personally I don't believe (and nor does Field) that this gives a good enough reason to believe in such things. Quine (who likes 'desert landscapes' in ontology) ends up believing that sets are real because of his argument. Not for me. |
18212 | Nominalists try to only refer to physical objects, or language, or mental constructions [Field,H] |
Full Idea: The most popular approach of nominalistically inclined philosophers is to try to reinterpret mathematics, so that its terms and quantifiers only make reference to, say, physical objects, or linguistic expressions, or mental constructions. | |
From: Hartry Field (Science without Numbers [1980], Prelim) | |
A reaction: I am keen on naturalism and empiricism, but only referring to physical objects is a non-starter. I think I favour constructions, derived from the experience of patterns, and abstracted, idealised and generalised. Field says application is the problem. |
10261 | The application of mathematics only needs its possibility, not its truth [Field,H, by Shapiro] |
Full Idea: Field argues that to account for the applicability of mathematics, we need to assume little more than the possibility of the mathematics, not its truth. | |
From: report of Hartry Field (Science without Numbers [1980]) by Stewart Shapiro - Philosophy of Mathematics 7.2 | |
A reaction: Very persuasive. We can apply chess to real military situations, provided that chess isn't self-contradictory (or even naturally impossible?). |
18218 | Hilbert explains geometry, by non-numerical facts about space [Field,H] |
Full Idea: Facts about geometric laws receive satisfying explanations, by the intrinsic facts about physical space, i.e. those laid down without reference to numbers in Hilbert's axioms. | |
From: Hartry Field (Science without Numbers [1980], 3) | |
A reaction: Hilbert's axioms mention points, betweenness, segment-congruence and angle-congruence (Field 25-26). Field cites arithmetic and geometry (as well as Newtonian mechanics) as not being dependent on number. |
9623 | Field needs a semantical notion of second-order consequence, and that needs sets [Brown,JR on Field,H] |
Full Idea: Field needs the notion of logical consequence in second-order logic, but (since this is not recursively axiomatizable) this is a semantical notion, which involves the idea of 'true in all models', a set-theoretic idea if there ever was one. | |
From: comment on Hartry Field (Science without Numbers [1980], Ch.4) by James Robert Brown - Philosophy of Mathematics | |
A reaction: Brown here summarises a group of critics. Field was arguing for modern nominalism, that actual numbers could (in principle) be written out of the story, as useful fictions. Popper's attempt to dump induction seemed to need induction. |
18215 | It seems impossible to explain the idea that the conclusion is contained in the premises [Field,H] |
Full Idea: No clear explanation of the idea that the conclusion was 'implicitly contained in' the premises was ever given, and I do not believe that any clear explanation is possible. | |
From: Hartry Field (Science without Numbers [1980], 1) |
18216 | Abstractions can form useful counterparts to concrete statements [Field,H] |
Full Idea: Abstract entities are useful because we can use them to formulate abstract counterparts of concrete statements. | |
From: Hartry Field (Science without Numbers [1980], 3) | |
A reaction: He defends the abstract statements as short cuts. If the concrete statements were 'true', then it seems likely that the abstract counterparts will also be true, which is not what fictionalism claims. |
18214 | Mathematics is only empirical as regards which theory is useful [Field,H] |
Full Idea: Mathematics is in a sense empirical, but only in the rather Pickwickian sense that is an empirical question as to which mathematical theory is useful. | |
From: Hartry Field (Science without Numbers [1980], 1) | |
A reaction: Field wants mathematics to be fictions, and not to be truths. But can he give an account of 'useful' that does not imply truth? Only in a rather dubiously pragmatist way. A novel is not useful. |
18210 | Why regard standard mathematics as truths, rather than as interesting fictions? [Field,H] |
Full Idea: Why regard the axioms of standard mathematics as truths, rather than as fictions that for a variety of reasons mathematicians have become interested in? | |
From: Hartry Field (Science without Numbers [1980], p.viii) |
18211 | You can reduce ontological commitment by expanding the logic [Field,H] |
Full Idea: One can often reduce one's ontological commitments by expanding one's logic. | |
From: Hartry Field (Science without Numbers [1980], p.ix) | |
A reaction: I don't actually understand this idea, but that's never stopped me before. Clearly, this sounds like an extremely interesting thought, and hence I should aspire to understand it. So I do aspire to understand it. First, how do you 'expand' a logic? |
15095 | A property's causal features are essential, and only they fix its identity [Shoemaker] |
Full Idea: The view I now favour says that the causal features of a property, both forward-looking and backward-looking, are essential to it. And it says that properties having the same causal features are identical. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], III) | |
A reaction: In this formulation we have essentialism about properties, as well as essentialism about the things which have the properties. |
15097 | I claim that a property has its causal features in all possible worlds [Shoemaker] |
Full Idea: The controversial claim of my theory is that the causal features of properties are essential to them - are features that they have in all possible worlds. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], III) | |
A reaction: One problem is that a property can come in degrees, so what degree of the property is necessary to it? It is better to assign this claim to the fundamental properties (which are best called 'powers'). |
8959 | Field presumes properties can be eliminated from science [Field,H, by Szabó] |
Full Idea: Field regards the eliminability of apparent reference to properties from the language of science as a foregone result. | |
From: report of Hartry Field (Science without Numbers [1980]) by Zoltán Gendler Szabó - Nominalism 5.1 n50 | |
A reaction: Field is a nominalist who also denies the existence of mathematics as part of science. He has a taste for ontological 'desert landscapes'. I have no idea what a property really is, so I think he is on to something. |
15094 | I now deny that properties are cluster of powers, and take causal properties as basic [Shoemaker] |
Full Idea: I now reject the formulation of the causal theory which says that a property is a cluster of conditional powers. That has a reductionist flavour, which is a cheat. We need properties to explain conditional powers, so properties won't reduce. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], III) | |
A reaction: [compressed wording] I agree with Mumford and Anjum in preferring his earlier formulation. I think properties are broad messy things, whereas powers can be defined more precisely, and seem to have more stability in nature. |
18213 | Abstract objects are only applicable to the world if they are impure, and connect to the physical [Field,H] |
Full Idea: To be able to apply any postulated abstract entities to the physical world, we need impure abstact entities, e.g. functions that map physical objects into pure abstract objects. | |
From: Hartry Field (Science without Numbers [1980], 1) | |
A reaction: I am a fan of 'impure metaphysics', and this pinpoints my reason very nicely. |
15099 | If something is possible, but not nomologically possible, we need metaphysical possibility [Shoemaker] |
Full Idea: If it is possible that there could be possible states of affairs that are not nomologically possible, don't we therefore need a notion of metaphysical possibility that outruns nomological possibility? | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], VI) | |
A reaction: Shoemaker rejects this possibility (p.425). I sympathise. So there is 'natural' possibility (my preferred term), which is anything which stuff, if it exists, could do, and 'logical' possibility, which is anything that doesn't lead to contradiction. |
15101 | Once you give up necessity as a priori, causal necessity becomes the main type of necessity [Shoemaker] |
Full Idea: Once the obstacle of the deeply rooted conviction that necessary truths should be knowable a priori is removed, ...causal necessity is (pretheoretically) the very paradigm of necessity, in ordinary usage and in dictionaries. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], VII) | |
A reaction: The a priori route seems to lead to logical necessity, just by doing a priori logic, and also to metaphysical necessity, by some sort of intuitive vision. This is a powerful idea of Shoemaker's (implied, of course, in Kripke). |
15098 | Empirical evidence shows that imagining a phenomenon can show it is possible [Shoemaker] |
Full Idea: We have abundant empirical evidence that when we can imagine some phenomenal situation, e.g., imagine things appearing certain ways, such a situation could actually exist. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], VI) | |
A reaction: There seem to be good reasons for holding the opposite view too. We can imagine gold appearing to be all sorts of colours, but that doesn't make it possible. What does empirical evidence really tell us here? |
15100 | Imagination reveals conceptual possibility, where descriptions avoid contradiction or incoherence [Shoemaker] |
Full Idea: Imaginability can give us access to conceptual possibility, when we come to believe situations to be conceptually possible by reflecting on their descriptions and seeing no contradiction or incoherence. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], VI) | |
A reaction: If take the absence of contradiction to indicate 'logical' possibility, but the absence of incoherence is more interesting, even if it is a bit vague. He is talking of 'situations', which I take to be features of reality. A priori synthetic? |
15096 | 'Grue' only has causal features because of its relation to green [Shoemaker] |
Full Idea: Perhaps 'grue' has causal features, but only derivatively, in virtue of its relation to green. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], III) | |
A reaction: I take grue to be a behaviour, and not a property at all. The problem only arises because the notion of a 'property' became too lax. Presumably Shoemaker should also mention blue in his account. |
18222 | Beneath every extrinsic explanation there is an intrinsic explanation [Field,H] |
Full Idea: A plausible methodological principle is that underlying every good extrinsic explanation there is an intrinsic explanation. | |
From: Hartry Field (Science without Numbers [1980], 5) | |
A reaction: I'm thinking that Hartry Field is an Aristotelian essentialist, though I bet he would never admit it. |
9917 | 'Abstract' is unclear, but numbers, functions and sets are clearly abstract [Field,H] |
Full Idea: The term 'abstract entities' may not be entirely clear, but one thing that does seem clear is that such alleged entities as numbers, functions and sets are abstract. | |
From: Hartry Field (Science without Numbers [1980], p.1), quoted by JP Burgess / G Rosen - A Subject with No Object I.A.1.a | |
A reaction: Field firmly denies the existence of such things. Sets don't seem a great problem, if the set is a herd of elephants, but the null and singleton sets show up the difficulties. |
15093 | We might say laws are necessary by combining causal properties with Armstrong-Dretske-Tooley laws [Shoemaker] |
Full Idea: One way to get the conclusion that laws are necessary is to combine my view of properties with the view of Armstrong, Dretske and Tooley, that laws are, or assert, relations between properties. | |
From: Sydney Shoemaker (Causal and Metaphysical Necessity [1998], I) | |
A reaction: This is interesting, because Armstrong in particular wants the necessity to arise from relations between properties as universals, but if we define properties causally, and make them necessary, we might get the same result without universals. |
18223 | In theories of fields, space-time points or regions are causal agents [Field,H] |
Full Idea: According to theories that take the notion of a field seriously, space-time points or regions are fully-fledge causal agents. | |
From: Hartry Field (Science without Numbers [1980], n 23) |
18220 | Both philosophy and physics now make substantivalism more attractive [Field,H] |
Full Idea: In general, it seems to me that recent developments in both philosophy and physics have made substantivalism a much more attractive position than it once was. | |
From: Hartry Field (Science without Numbers [1980], 4) | |
A reaction: I'm intrigued as to what philosophical developments are involved in this. The arrival of fields is the development in physics. |
18219 | Relational space is problematic if you take the idea of a field seriously [Field,H] |
Full Idea: The problem of the relational view of space is especially acute in the context of physical theories that take the notion of a field seriously, e.g. classical electromagnetic theory. | |
From: Hartry Field (Science without Numbers [1980], 4) | |
A reaction: In the Leibniz-Clarke debate I sided with the Newtonian Clarke (defending absolute space), and it looks like modern science agrees with me. Nothing exists purely as relations. |