37 ideas
| 17275 | Realist metaphysics concerns what is real; naive metaphysics concerns natures of things [Fine,K] |
| Full Idea: We may broadly distinguish between two main branches of metaphysics: the 'realist' or 'critical' branch is concerned with what is real (tense, values, numbers); the 'naive' or 'pre-critical' branch concerns natures of things irrespective of reality. | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: [compressed] The 'natures' of things are presumably the essences. He cites 3D v 4D objects, and the status of fictional characters, as examples of the second type. Fine says ground is central to realist metaphysics. |
| 17282 | Truths need not always have their source in what exists [Fine,K] |
| Full Idea: There is no reason in principle why the ultimate source of what is true should always lie in what exists. | |
| From: Kit Fine (Guide to Ground [2012], 1.03) | |
| A reaction: This seems to be the weak point of the truthmaker theory, since truths about non-existence are immediately in trouble. Saying reality makes things true is one thing, but picking out a specific bit of it for each truth is not so easy. |
| 17283 | If the truth-making relation is modal, then modal truths will be grounded in anything [Fine,K] |
| Full Idea: The truth-making relation is usually explicated in modal terms, ...but this lets in far too much. Any necessary truth will be grounded by anything. ...The fact that singleton Socrates exists will be a truth-maker for the proposition that Socrates exists. | |
| From: Kit Fine (Guide to Ground [2012], 1.03) | |
| A reaction: If truth-makers are what has to 'exist' for something to be true, then maybe nothing must exist for a necessity to be true - in which case it has no truth maker. Or maybe 2 and 4 must 'exist' for 2+2=4? |
| 17286 | Logical consequence is verification by a possible world within a truth-set [Fine,K] |
| Full Idea: Under the possible worlds semantics for logical consequence, each sentence of a language is associated with a truth-set of possible worlds in which it is true, and then something is a consequence if one of these worlds verifies it. | |
| From: Kit Fine (Guide to Ground [2012], 1.10) | |
| A reaction: [compressed, and translated into English; see Fine for more symbolic version; I'm more at home in English] |
| 8729 | Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro] |
| Full Idea: Intuitionists in mathematics deny excluded middle, because it is symptomatic of faith in the transcendent existence of mathematical objects and/or the truth of mathematical statements. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2) | |
| A reaction: There are other problems with excluded middle, such as vagueness, but on the whole I, as a card-carrying 'realist', am committed to the law of excluded middle. |
| 8763 | The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro] |
| Full Idea: It is surely wise to identify the positions in the natural numbers structure with their counterparts in the integer, rational, real and complex number structures. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2) | |
| A reaction: The point is that this might be denied, since 3, 3/1, 3.00.., and -3*i^2 are all arrived at by different methods of construction. Natural 3 has a predecessor, but real 3 doesn't. I agree, intuitively, with Shapiro. Russell (1919) disagreed. |
| 18249 | Cauchy gave a formal definition of a converging sequence. [Shapiro] |
| Full Idea: A sequence a1,a2,... of rational numbers is 'Cauchy' if for each rational number ε>0 there is a natural number N such that for all natural numbers m, n, if m>N and n>N then -ε < am - an < ε. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 7.2 n4) | |
| A reaction: The sequence is 'Cauchy' if N exists. |
| 8764 | Categories are the best foundation for mathematics [Shapiro] |
| Full Idea: There is a dedicated contingent who hold that the category of 'categories' is the proper foundation for mathematics. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.3 n7) | |
| A reaction: He cites Lawvere (1966) and McLarty (1993), the latter presenting the view as a form of structuralism. I would say that the concept of a category will need further explication, and probably reduce to either sets or relations or properties. |
| 8762 | Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro] |
| Full Idea: Zermelo said that for each number n, its successor is the singleton of n, so 3 is {{{null}}}, and 1 is not a member of 3. Von Neumann said each number n is the set of numbers less than n, so 3 is {null,{null},{null,{null}}}, and 1 is a member of 3. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2) | |
| A reaction: See Idea 645 - Zermelo could save Plato from the criticisms of Aristotle! These two accounts are cited by opponents of the set-theoretical account of numbers, because it seems impossible to arbitrate between them. |
| 8760 | Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro] |
| Full Idea: The structuralist vigorously rejects any sort of ontological independence among the natural numbers; the essence of a natural number is its relations to other natural numbers. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1) | |
| A reaction: This seems to place the emphasis on ordinals (what order?) rather than on cardinality (how many?). I am strongly inclined to think that this is the correct view, though you can't really have relations if there is nothing to relate. |
| 8761 | A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro] |
| Full Idea: A 'system' is a collection of objects with certain relations among them; a 'pattern' or 'structure' is the abstract form of a system, highlighting the interrelationships and ignoring any features they do not affect how they relate to other objects. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1) | |
| A reaction: Note that 'ignoring' features is a psychological account of abstraction, which (thanks to Frege and Geach) is supposed to be taboo - but which I suspect is actually indispensable in any proper account of thought and concepts. |
| 8744 | Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro] |
| Full Idea: The thesis that principles of arithmetic are derivable from the laws of logic runs against a now common view that logic itself has no ontology. There are no particular logical objects. From this perspective logicism is a non-starter. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 5.1) | |
| A reaction: This criticism strikes me as utterly devastating. There are two routes to go: prove that logic does have an ontology of objects (what would they be?), or - better - deny that arithmetic contains any 'objects'. Or give up logicism. |
| 8749 | Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro] |
| Full Idea: Term Formalism is the view that mathematics is just about characters or symbols - the systems of numerals and other linguistic forms. ...This will cover integers and rational numbers, but what are real numbers supposed to be, if they lack names? | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.1) | |
| A reaction: Real numbers (such as pi and root-2) have infinite decimal expansions, so we can start naming those. We could also start giving names like 'Harry' to other reals, though it might take a while. OK, I give up. |
| 8750 | Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro] |
| Full Idea: Game Formalism likens mathematics to chess, where the 'content' of mathematics is exhausted by the rules of operating with its language. ...This, however, leaves the problem of why the mathematical games are so useful to the sciences. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.2) | |
| A reaction: This thought pushes us towards structuralism. It could still be a game, but one we learned from observing nature, which plays its own games. Chess is, after all, modelled on warfare. |
| 8752 | Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro] |
| Full Idea: The Deductivist version of formalism (sometimes called 'if-thenism') says that the practice of mathematics consists of determining logical consequences of otherwise uninterpreted axioms. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 6.2) | |
| A reaction: [Hilbert is the source] More plausible than Term or Game Formalism (qv). It still leaves the question of why it seems applicable to nature, and why those particular axioms might be chosen. In some sense, though, it is obviously right. |
| 8753 | Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro] |
| Full Idea: Critics commonly complain that the intuitionist restrictions cripple the mathematician. On the other hand, intuitionist mathematics allows for many potentially important distinctions not available in classical mathematics, and is often more subtle. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 7.1) | |
| A reaction: The main way in which it cripples is its restriction on talk of infinity ('Cantor's heaven'), which was resented by Hilbert. Since high-level infinities are interesting, it would be odd if we were not allowed to discuss them. |
| 8731 | Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro] |
| Full Idea: I classify conceptualists according to what they say about properties or concepts. If someone classified properties as existing independent of language I would classify her as a realist in ontology of mathematics. Or they may be idealists or nominalists. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 2.2.1) | |
| A reaction: In other words, Shapiro wants to eliminate 'conceptualist' as a useful label in philosophy of mathematics. He's probably right. All thought involves concepts, but that doesn't produce a conceptualist theory of, say, football. |
| 8730 | 'Impredicative' definitions refer to the thing being described [Shapiro] |
| Full Idea: A definition of a mathematical entity is 'impredicative' if it refers to a collection that contains the defined entity. The definition of 'least upper bound' is impredicative as it refers to upper bounds and characterizes a member of this set. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2) | |
| A reaction: The big question is whether mathematics can live with impredicative definitions, or whether they threaten to be viciously circular, and undermine the whole enterprise. |
| 17272 | 2+2=4 is necessary if it is snowing, but not true in virtue of the fact that it is snowing [Fine,K] |
| Full Idea: It is necessary that if it is snowing then 2+2=4, but the fact that 2+2=4 does not obtain in virtue of the fact that it is snowing. | |
| From: Kit Fine (Guide to Ground [2012], 1.01) | |
| A reaction: Critics dislike 'in virtue of' (as vacuous), but I can't see how you can disagree with this obvervation of Fine's. You can hardly eliminate the word 'because' from English, or say p is because of some object. We demand the right to keep asking 'why?'! |
| 17276 | If you say one thing causes another, that leaves open that the 'other' has its own distinct reality [Fine,K] |
| Full Idea: It will not do to say that the physical is causally determinative of the mental, since that leaves open the possibility that the mental has a distinct reality over and above that of the physical. | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: The context is a defence of grounding, so that if we say the mind is 'grounded' in the brain, we are saying rather more than merely that it is caused by the brain. A ghost might be 'caused' by a bar of soap. Nice. |
| 17284 | An immediate ground is the next lower level, which gives the concept of a hierarchy [Fine,K] |
| Full Idea: It is the notion of 'immediate' ground that provides us with our sense of a ground-theoretic hierarchy. For any truth, we can take its immediate grounds to be at the next lower level. | |
| From: Kit Fine (Guide to Ground [2012], 1.05 'Mediate') | |
| A reaction: Are the levels in the reality, the structure or the descriptions? I vote for the structure. I'm defending the idea that 'essence' picks out the bottom of a descriptive level. |
| 17285 | 'Strict' ground moves down the explanations, but 'weak' ground can move sideways [Fine,K] |
| Full Idea: We might think of strict ground as moving us down in the explanatory hierarchy. ...Weak ground, on the other hand, may also move us sideways in the explanatory hierarchy. | |
| From: Kit Fine (Guide to Ground [2012], 1.05 'Weak') | |
| A reaction: This seems to me rather illuminating. For example, is the covering law account of explanation a 'sideways' move in explanation. Are inductive generalities mere 'sideways' accounts. Both fail to dig deeper. |
| 17288 | We learn grounding from what is grounded, not what does the grounding [Fine,K] |
| Full Idea: It is the fact to be grounded that 'points' to its ground and not the grounds that point to what they ground. | |
| From: Kit Fine (Guide to Ground [2012], 1.11) | |
| A reaction: What does the grounding may ground all sorts of other things, but what is grounded only has one 'full' (as opposed to 'partial', in Fine's terminology) ground. He says this leads to a 'top-down' approach to the study of grounds. |
| 17281 | If grounding is a relation it must be between entities of the same type, preferably between facts [Fine,K] |
| Full Idea: In so far as ground is regarded as a relation it should be between entities of the same type, and the entities should probably be taken as worldly entities, such as facts, rather than as representational entities, such as propositions. | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: That's more like it (cf. Idea 17280). The consensus of this discussion seems to point to facts as the best relata, for all the vagueness of facts, and the big question of how fine-grained facts should be (and how dependent they are on descriptions). |
| 17280 | Ground is best understood as a sentence operator, rather than a relation between predicates [Fine,K] |
| Full Idea: Ground is perhaps best regarded as an operation (signified by an operator on sentences) rather than as a relation (signified by a predicate) | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: Someone in this book (Koslicki?) says this is to avoid metaphysical puzzles over properties. I don't like the idea, because it makes grounding about sentences when it should be about reality. Fine is so twentieth century. Audi rests ground on properties. |
| 17290 | Only metaphysical grounding must be explained by essence [Fine,K] |
| Full Idea: If the grounding relation is not metaphysical (such as normative or natural grounding), there is no need for there to be an explanation of its holding in terms of the essentialist nature of the items involved. | |
| From: Kit Fine (Guide to Ground [2012], 1.11) | |
| A reaction: He accepts that some things have partial grounds in different areas of reality. |
| 17274 | Philosophical explanation is largely by ground (just as cause is used in science) [Fine,K] |
| Full Idea: For philosophers interested in explanation - of what accounts for what - it is largely through the notion of ontological ground that such questions are to be pursued. Ground, if you like, stands to philosophy as cause stands to science. | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: Why does the ground have to be 'ontological'? It isn't the existence of the snow that makes me cold, but the fact that I am lying in it. Better to talk of 'factual' ground (or 'determinative' ground), and then causal grounds are a subset of those? |
| 17278 | We can only explain how a reduction is possible if we accept the concept of ground [Fine,K] |
| Full Idea: It is only by embracing the concept of a ground as a metaphysical form of explanation in its own right that one can adequately explain how a reduction of the reality of one thing to another should be understood. | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: I love that we are aiming to say 'how' a reduction should be understood, and not just 'that' it exists. I'm not sure about Fine's emphasis on explaining 'realities', when I think we are after more like structural relations or interconnected facts. |
| 17287 | Facts, such as redness and roundness of a ball, can be 'fused' into one fact [Fine,K] |
| Full Idea: Given any facts, there will be a fusion of those facts. Given the facts that the ball is red and that it is round, there is a fused fact that it is 'red and round'. | |
| From: Kit Fine (Guide to Ground [2012], 1.10) | |
| A reaction: This is how we make 'units' for counting. Any type of thing which can be counted can be fused, such as the first five prime numbers, forming the 'first' group for some discussion. Any objects can be fused to make a unit - but is it thereby a 'unity'? |
| 17279 | Even a three-dimensionalist might identify temporal parts, in their thinking [Fine,K] |
| Full Idea: Even the three-dimensionalist might be willing to admit that material things have temporal parts. For given any persisting object, he might suppose that 'in thought' we could mark out its temporal segments or parts. | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: A big problem with temporal parts is how thin they are. Hawley says they are as fine-grained as time itself, but what if time has no grain? How thin can you 'think' a temporal part to be? Fine says imagined parts are grounded in things, not vice versa. |
| 17273 | Each basic modality has its 'own' explanatory relation [Fine,K] |
| Full Idea: I am inclined to the view that ....each basic modality should be associated with its 'own' explanatory relation. | |
| From: Kit Fine (Guide to Ground [2012], 1.01) | |
| A reaction: He suggests that 'grounding' connects the various explanatory relations of the different modalities. I like this a lot. Why assert any necessity without some concept of where the necessity arises, and hence where it is grounded? You've got to eat. |
| 17289 | Every necessary truth is grounded in the nature of something [Fine,K] |
| Full Idea: It might be held as a general thesis that every necessary truth is grounded in the nature of certain items. | |
| From: Kit Fine (Guide to Ground [2012], 1.11) | |
| A reaction: [He cites his own 1994 for this] I'm not sure if I can embrace the 'every' in this. I would only say, more cautiously, that I can only make sense of necessity claims when I see their groundings - and I don't take a priori intuition as decent grounding. |
| 8725 | Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro] |
| Full Idea: Rationalism is a long-standing school that can be characterized as an attempt to extend the perceived methodology of mathematics to all of knowledge. | |
| From: Stewart Shapiro (Thinking About Mathematics [2000], 1.1) | |
| A reaction: Sometimes called 'Descartes's Dream', or the 'Enlightenment Project', the dream of proving everything. Within maths, Hilbert's Programme aimed for the same certainty. Idea 22 is the motto for the opposition to this approach. |
| 17291 | We explain by identity (what it is), or by truth (how things are) [Fine,K] |
| Full Idea: I think it should be recognised that there are two fundamentally different types of explanation; one is of identity, or of what something is; and the other is of truth, or of how things are. | |
| From: Kit Fine (Guide to Ground [2012], 1.11) |
| 17271 | Is there metaphysical explanation (as well as causal), involving a constitutive form of determination? [Fine,K] |
| Full Idea: In addition to scientific or causal explanation, there maybe a distinctive kind of metaphysical explanation, in which explanans and explanandum are connected, not through some causal mechanism, but through some constitutive form of determination. | |
| From: Kit Fine (Guide to Ground [2012], Intro) | |
| A reaction: I'm unclear why determination has to be 'constitutive', since I would take determination to be a family of concepts, with constitution being one of them, as when chess pieces determine a chess set. Skip 'metaphysical'; just have Determinative Explanation. |
| 17277 | If mind supervenes on the physical, it may also explain the physical (and not vice versa) [Fine,K] |
| Full Idea: It is not enough to require that the mental should modally supervene on the physical, since that still leaves open the possibility that the physical is itself ultimately to be understood in terms of the mental. | |
| From: Kit Fine (Guide to Ground [2012], 1.02) | |
| A reaction: See Horgan on supervenience. Supervenience is a question, not an answer. The first question is whether the supervenience is mutual, and if not, which 'direction' does it go in? |
| 1515 | Pythagoreans believe it is absurd to seek for goodness anywhere except with the gods [Iamblichus] |
| Full Idea: The thinking behind Pythagorean philosophy is that people behave in an absurd fashion if they try to find any source for the good other than the gods. | |
| From: Iamblichus (Life of Pythagoras [c.290], 137) |