45 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? |
| 17749 | Post proved the consistency of propositional logic in 1921 [Walicki] |
| Full Idea: A proof of the consistency of propositional logic was given by Emil Post in 1921. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], History E.2.1) |
| 17765 | Propositional language can only relate statements as the same or as different [Walicki] |
| Full Idea: Propositional language is very rudimentary and has limited powers of expression. The only relation between various statements it can handle is that of identity and difference. As are all the same, but Bs can be different from As. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 7 Intro) | |
| A reaction: [second sentence a paraphrase] In predicate logic you could represent two statements as being the same except for one element (an object or predicate or relation or quantifier). |
| 17764 | Boolean connectives are interpreted as functions on the set {1,0} [Walicki] |
| Full Idea: Boolean connectives are interpreted as functions on the set {1,0}. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 5.1) | |
| A reaction: 1 and 0 are normally taken to be true (T) and false (F). Thus the functions output various combinations of true and false, which are truth tables. |
| 17752 | The empty set is useful for defining sets by properties, when the members are not yet known [Walicki] |
| Full Idea: The empty set is mainly a mathematical convenience - defining a set by describing the properties of its members in an involved way, we may not know from the very beginning what its members are. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 1.1) |
| 17753 | The empty set avoids having to take special precautions in case members vanish [Walicki] |
| Full Idea: Without the assumption of the empty set, one would often have to take special precautions for the case where a set happened to contain no elements. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 1.1) | |
| A reaction: Compare the introduction of the concept 'zero', where special precautions are therefore required. ...But other special precautions are needed without zero. Either he pays us, or we pay him, or ...er. Intersecting sets need the empty set. |
| 17759 | Ordinals play the central role in set theory, providing the model of well-ordering [Walicki] |
| Full Idea: Ordinals play the central role in set theory, providing the paradigmatic well-orderings. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3) | |
| A reaction: When you draw the big V of the iterative hierarchy of sets (built from successive power sets), the ordinals are marked as a single line up the middle, one ordinal for each level. |
| 17741 | To determine the patterns in logic, one must identify its 'building blocks' [Walicki] |
| Full Idea: In order to construct precise and valid patterns of arguments one has to determine their 'building blocks'. One has to identify the basic terms, their kinds and means of combination. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], History Intro) | |
| A reaction: A deceptively simple and important idea. All explanation requires patterns and levels, and it is the idea of building blocks which makes such things possible. It is right at the centre of our grasp of everything. |
| 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] |
| 12394 | If the result is bad, we change the rule; if we like the rule, we reject the result [Goodman] |
| Full Idea: A rule is amended if it yields an inference we are unwilling to accept; an inference is rejected if it violates a rule we are unwilling to amend. | |
| From: Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954], p.64) | |
| A reaction: This is clearly in tune with Quine's assertion that logic is potentially revisable, and the idea is pragmatist in spirit. It is hard to deny that intuitions about what makes a good argument control our logic. I say the world controls our intuitions. |
| 17747 | A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki] |
| Full Idea: A specification of a domain of objects, and of the rules for interpreting the symbols of a logical language in this domain such that all the theorems of the logical theory are true is said to be a 'model' of the theory. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], History E.1.3) | |
| A reaction: The basic ideas of this emerged 1915-30, but it needed Tarski's account of truth to really get it going. |
| 17748 | The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki] |
| Full Idea: The L-S Theorem is ...a shocking result, since it implies that any consistent formal theory of everything - even about biology, physics, sets or the real numbers - can just as well be understood as being about natural numbers. It says nothing more. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], History E.2) | |
| A reaction: Illuminating. Particularly the point that no theory about the real numbers can say anything more than a theory about the natural numbers. So the natural numbers contain all the truths we can ever express? Eh????? |
| 17761 | A compact axiomatisation makes it possible to understand a field as a whole [Walicki] |
| Full Idea: Having such a compact [axiomatic] presentation of a complicated field [such as Euclid's], makes it possible to relate not only to particular theorems but also to the whole field as such. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 4.1) |
| 17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
| Full Idea: Axiomatic systems, their primitive terms and proofs, are purely syntactic, that is, do not presuppose any interpretation. ...[142] They never address the world directly, but address a possible semantic model which formally represents the world. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 4.1) |
| 17758 | Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki] |
| Full Idea: An ordinal can be defined as a transitive set of transitive sets, or else, as a transitive set totally ordered by set inclusion. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3) |
| 17755 | Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki] |
| Full Idea: The collection of ordinals is defined inductively: Basis: the empty set is an ordinal; Ind: for an ordinal x, the union with its singleton is also an ordinal; and any arbitrary (possibly infinite) union of ordinals is an ordinal. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3) | |
| A reaction: [symbolism translated into English] Walicki says they are called 'ordinal numbers', but are in fact a set. |
| 17756 | The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki] |
| Full Idea: We can form infinite ordinals by taking unions of ordinals. We can thus form 'limit ordinals', which have no immediate predecessor. ω is the first (the union of all finite ordinals), ω + ω = sω is second, 3ω the third.... | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3) |
| 17760 | Two infinite ordinals can represent a single infinite cardinal [Walicki] |
| Full Idea: There may be several ordinals for the same cardinality. ...Two ordinals can represent different ways of well-ordering the same number (aleph-0) of elements. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3) | |
| A reaction: This only applies to infinite ordinals and cardinals. For the finite, the two coincide. In infinite arithmetic the rules are different. |
| 17757 | Members of ordinals are ordinals, and also subsets of ordinals [Walicki] |
| Full Idea: Every member of an ordinal is itself an ordinal, and every ordinal is a transitive set (its members are also its subsets; a member of a member of an ordinal is also a member of the ordinal). | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3) |
| 17762 | In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki] |
| Full Idea: Since non-Euclidean geometry preserves all Euclid's postulates except the fifth one, all the theorems derived without the use of the fifth postulate remain valid. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 4.1) |
| 17754 | Inductive proof depends on the choice of the ordering [Walicki] |
| Full Idea: Inductive proof is not guaranteed to work in all cases and, particularly, it depends heavily on the choice of the ordering. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.1.1) | |
| A reaction: There has to be an well-founded ordering for inductive proofs to be possible. |
| 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'? |
| 14292 | Dispositions seem more ethereal than behaviour; a non-occult account of them would be nice [Goodman] |
| Full Idea: Dispositions of a thing are as important to us as overt behaviour, but they strike us by comparison as rather ethereal. So we are moved to enquire whether we can bring them down to earth, and explain disposition terms without reference to occult powers. | |
| From: Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954], II.3) | |
| A reaction: Mumford quotes this at the start of his book on dispositions, as his agenda. I suspect that the 'occult' aspect crept in because dispositions were based on powers, and the dominant view was that these were the immediate work of God. |
| 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. |
| 17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
| Full Idea: The link between time and modality was severed by Duns Scotus, who proposed a notion of possibility based purely on the notion of semantic consistency. 'Possible' means for him logically possible, that is, not involving contradiction. | |
| From: Michal Walicki (Introduction to Mathematical Logic [2012], History B.4) |
| 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. |
| 18749 | Goodman argued that the confirmation relation can never be formalised [Goodman, by Horsten/Pettigrew] |
| Full Idea: Goodman constructed arguments that purported to show that a satisfactory syntactic analysis of the confirmation relation can never be found. In response, philosophers of science tried to model it in probabilistic terms. | |
| From: report of Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954]) by Horsten,L/Pettigrew,R - Mathematical Methods in Philosophy 4 | |
| A reaction: I take this idea to say that Bayesianism was developed in response to the grue problem. This is an interesting light on 'grue', which never bothered me much. The point is it scuppered formal attempts to model induction. |
| 17646 | Goodman showed that every sound inductive argument has an unsound one of the same form [Goodman, by Putnam] |
| Full Idea: Goodman has shown that no purely formal criterion can distinguish arguments that are intuitively sound inductive arguments for unsound ones: for every sound one there is an unsound one of the same form. The predicates in the argument make the difference. | |
| From: report of Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954]) by Hilary Putnam - Why there isn't a ready-made world 'Causation' | |
| A reaction: This is to swallow grue whole. I think a bit more chewing is called for. By this date Putnam strikes me as a crazy relativist who has lost his grip on the world. Note the word 'formal' - but Putnam seems to think the argument is important. |
| 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? |
| 4794 | We don't use laws to make predictions, we call things laws if we make predictions with them [Goodman] |
| Full Idea: Rather than a sentence being used for prediction because it is a law, it is called a law because it is used for prediction. | |
| From: Nelson Goodman (Fact, Fiction and Forecast (4th ed) [1954], p.21), quoted by Stathis Psillos - Causation and Explanation §5.4 | |
| A reaction: This smacks of dodgy pragmatism, and sounds deeply wrong. The perception of a law has to be prior to making the prediction. Why do we make the prediction, if we haven't spotted a law. Goodman is mesmerised by language instead of reality. |