98 ideas
| 4194 | Metaphysics is concerned with the fundamental structure of reality as a whole [Lowe] |
| Full Idea: Metaphysics is concerned with the fundamental structure of reality as a whole. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.2) | |
| A reaction: I think it is vital to hang on to this big definition, focusing on ontology, and not retreat (like Kant) to the epistemological question of how humans happen to see reality, even if we are stuck with being humans. |
| 4214 | Maybe such concepts as causation, identity and existence are primitive and irreducible [Lowe] |
| Full Idea: It may well be that after all our attempts at analysis, we have to accept the notions of causality, identity and existence as being primitive and irreducible. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.191) | |
| A reaction: They may be irreducible, but it seems possible that the relationships between them might be revealed (as between Platonic Forms). To exist is to have identity and causal powers? |
| 4222 | If all that exists is what is being measured, what about the people and instruments doing the measuring? [Lowe] |
| Full Idea: If we think, in a positivistic spirit, that only measurements and observations exist, this is strikingly naïve. The scientists and their instruments can't be composed merely of measurements. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.234) | |
| A reaction: A strong rebuff to crude positivism and 'operationalism'. Such mistakes are the usual confusion of epistemology and ontology. |
| 4217 | It is more extravagant, in general, to revise one's logic than to augment one's ontology [Lowe] |
| Full Idea: It is more extravagant, in general, to revise one's logic than to augment one's ontology. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.219) | |
| A reaction: Meaning there are stronger principles of thought which can trump Ockham's Razor. A few more entities won't hurt. Sound right. |
| 10987 | Three traditional names of rules are 'Simplification', 'Addition' and 'Disjunctive Syllogism' [Read] |
| Full Idea: Three traditional names for rules are 'Simplification' (P from 'P and Q'), 'Addition' ('P or Q' from P), and 'Disjunctive Syllogism' (Q from 'P or Q' and 'not-P'). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 11004 | Necessity is provability in S4, and true in all worlds in S5 [Read] |
| Full Idea: In S4 necessity is said to be informal 'provability', and in S5 it is said to be 'true in every possible world'. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: It seems that the S4 version is proof-theoretic, and the S5 version is semantic. |
| 11018 | There are fuzzy predicates (and sets), and fuzzy quantifiers and modifiers [Read] |
| Full Idea: In fuzzy logic, besides fuzzy predicates, which define fuzzy sets, there are also fuzzy quantifiers (such as 'most' and 'few') and fuzzy modifiers (such as 'usually'). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) |
| 11011 | Same say there are positive, negative and neuter free logics [Read] |
| Full Idea: It is normal to classify free logics into three sorts; positive free logics (some propositions with empty terms are true), negative free logics (they are false), and neuter free logics (they lack truth-value), though I find this unhelpful and superficial. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) |
| 7785 | The use of plurals doesn't commit us to sets; there do not exist individuals and collections [Boolos] |
| Full Idea: We should abandon the idea that the use of plural forms commits us to the existence of sets/classes… Entities are not to be multiplied beyond necessity. There are not two sorts of things in the world, individuals and collections. | |
| From: George Boolos (To be is to be the value of a variable.. [1984]), quoted by Henry Laycock - Object | |
| A reaction: The problem of quantifying over sets is notoriously difficult. Try http://plato.stanford.edu/entries/object/index.html. |
| 11020 | Realisms like the full Comprehension Principle, that all good concepts determine sets [Read] |
| Full Idea: Hard-headed realism tends to embrace the full Comprehension Principle, that every well-defined concept determines a set. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.8) | |
| A reaction: This sort of thing gets you into trouble with Russell's paradox (though that is presumably meant to be excluded somehow by 'well-defined'). There are lots of diluted Comprehension Principles. |
| 10699 | Does a bowl of Cheerios contain all its sets and subsets? [Boolos] |
| Full Idea: Is there, in addition to the 200 Cheerios in a bowl, also a set of them all? And what about the vast number of subsets of Cheerios? It is haywire to think that when you have some Cheerios you are eating a set. What you are doing is: eating the Cheerios. | |
| From: George Boolos (To be is to be the value of a variable.. [1984], p.72) | |
| A reaction: In my case Boolos is preaching to the converted. I am particularly bewildered by someone (i.e. Quine) who believes that innumerable sets exist while 'having a taste for desert landscapes' in their ontology. |
| 10986 | Not all validity is captured in first-order logic [Read] |
| Full Idea: We must recognise that first-order classical logic is inadequate to describe all valid consequences, that is, all cases in which it is impossible for the premisses to be true and the conclusion false. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: This is despite the fact that first-order logic is 'complete', in the sense that its own truths are all provable. |
| 10972 | The non-emptiness of the domain is characteristic of classical logic [Read] |
| Full Idea: The non-emptiness of the domain is characteristic of classical logic. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10225 | Monadic second-order logic might be understood in terms of plural quantifiers [Boolos, by Shapiro] |
| Full Idea: Boolos has proposed an alternative understanding of monadic, second-order logic, in terms of plural quantifiers, which many philosophers have found attractive. | |
| From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Philosophy of Mathematics 3.5 |
| 10736 | Boolos showed how plural quantifiers can interpret monadic second-order logic [Boolos, by Linnebo] |
| Full Idea: In an indisputable technical result, Boolos showed how plural quantifiers can be used to interpret monadic second-order logic. | |
| From: report of George Boolos (To be is to be the value of a variable.. [1984], Intro) by Øystein Linnebo - Plural Quantification Exposed Intro |
| 10780 | Any sentence of monadic second-order logic can be translated into plural first-order logic [Boolos, by Linnebo] |
| Full Idea: Boolos discovered that any sentence of monadic second-order logic can be translated into plural first-order logic. | |
| From: report of George Boolos (To be is to be the value of a variable.. [1984], §1) by Øystein Linnebo - Plural Quantification Exposed p.74 |
| 11024 | Semantics must precede proof in higher-order logics, since they are incomplete [Read] |
| Full Idea: For the realist, study of semantic structures comes before study of proofs. In higher-order logic is has to, for the logics are incomplete. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.9) | |
| A reaction: This seems to be an important general observation about any incomplete system, such as Peano arithmetic. You may dream the old rationalist dream of starting from the beginning and proving everything, but you can't. Start with truth and meaning. |
| 10985 | We should exclude second-order logic, precisely because it captures arithmetic [Read] |
| Full Idea: Those who believe mathematics goes beyond logic use that fact to argue that classical logic is right to exclude second-order logic. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10970 | A theory of logical consequence is a conceptual analysis, and a set of validity techniques [Read] |
| Full Idea: A theory of logical consequence, while requiring a conceptual analysis of consequence, also searches for a set of techniques to determine the validity of particular arguments. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10984 | Logical consequence isn't just a matter of form; it depends on connections like round-square [Read] |
| Full Idea: If classical logic insists that logical consequence is just a matter of the form, we fail to include as valid consequences those inferences whose correctness depends on the connections between non-logical terms (such as 'round' and 'square'). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: He suggests that an inference such as 'round, so not square' should be labelled as 'materially valid'. |
| 10697 | Identity is clearly a logical concept, and greatly enhances predicate calculus [Boolos] |
| Full Idea: Indispensable to cross-reference, lacking distinctive content, and pervading thought and discourse, 'identity' is without question a logical concept. Adding it to predicate calculus significantly increases the number and variety of inferences possible. | |
| From: George Boolos (To be is to be the value of a variable.. [1984], p.54) | |
| A reaction: It is not at all clear to me that identity is a logical concept. Is 'existence' a logical concept? It seems to fit all of Boolos's criteria? I say that all he really means is that it is basic to thought, but I'm not sure it drives the reasoning process. |
| 10973 | A theory is logically closed, which means infinite premisses [Read] |
| Full Idea: A 'theory' is any logically closed set of propositions, ..and since any proposition has infinitely many consequences, including all the logical truths, so that theories have infinitely many premisses. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: Read is introducing this as the essential preliminary to an account of the Compactness Theorem, which relates these infinite premisses to the finite. |
| 11007 | Quantifiers are second-order predicates [Read] |
| Full Idea: Quantifiers are second-order predicates. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) | |
| A reaction: [He calls this 'Frege's insight'] They seem to be second-order in Tarski's sense, that they are part of a metalanguage about the sentence, rather than being a part of the sentence. |
| 13671 | Second-order quantifiers are just like plural quantifiers in ordinary language, with no extra ontology [Boolos, by Shapiro] |
| Full Idea: Boolos proposes that second-order quantifiers be regarded as 'plural quantifiers' are in ordinary language, and has developed a semantics along those lines. In this way they introduce no new ontology. | |
| From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Foundations without Foundationalism 7 n32 | |
| A reaction: This presumably has to treat simple predicates and relations as simply groups of objects, rather than having platonic existence, or something. |
| 10978 | In second-order logic the higher-order variables range over all the properties of the objects [Read] |
| Full Idea: The defining factor of second-order logic is that, while the domain of its individual variables may be arbitrary, the range of the first-order variables is all the properties of the objects in its domain (or, thinking extensionally, of the sets objects). | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: The key point is that the domain is 'all' of the properties. How many properties does an object have. You need to decide whether you believe in sparse or abundant properties (I vote for very sparse indeed). |
| 10267 | We should understand second-order existential quantifiers as plural quantifiers [Boolos, by Shapiro] |
| Full Idea: Standard second-order existential quantifiers pick out a class or a property, but Boolos suggests that they be understood as a plural quantifier, like 'there are objects' or 'there are people'. | |
| From: report of George Boolos (To be is to be the value of a variable.. [1984]) by Stewart Shapiro - Philosophy of Mathematics 7.4 | |
| A reaction: This idea has potential application to mathematics, and Lewis (1991, 1993) 'invokes it to develop an eliminative structuralism' (Shapiro). |
| 10698 | Plural forms have no more ontological commitment than to first-order objects [Boolos] |
| Full Idea: Abandon the idea that use of plural forms must always be understood to commit one to the existence of sets of those things to which the corresponding singular forms apply. | |
| From: George Boolos (To be is to be the value of a variable.. [1984], p.66) | |
| A reaction: It seems to be an open question whether plural quantification is first- or second-order, but it looks as if it is a rewriting of the first-order. |
| 7806 | Boolos invented plural quantification [Boolos, by Benardete,JA] |
| Full Idea: Boolos virtually patented the new device of plural quantification. | |
| From: report of George Boolos (To be is to be the value of a variable.. [1984]) by José A. Benardete - Logic and Ontology | |
| A reaction: This would be 'there are some things such that...' |
| 10971 | A logical truth is the conclusion of a valid inference with no premisses [Read] |
| Full Idea: Logical truth is a degenerate, or extreme, case of consequence. A logical truth is the conclusion of a valid inference with no premisses, or a proposition in the premisses of an argument which is unnecessary or may be suppressed. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10988 | Any first-order theory of sets is inadequate [Read] |
| Full Idea: Any first-order theory of sets is inadequate because of the Löwenheim-Skolem-Tarski property, and the consequent Skolem paradox. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: The limitation is in giving an account of infinities. |
| 10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
| Full Idea: Classical logical consequence is compact, which means that any consequence of an infinite set of propositions (such as a theory) is a consequence of some finite subset of them. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10975 | Compactness does not deny that an inference can have infinitely many premisses [Read] |
| Full Idea: Compactness does not deny that an inference can have infinitely many premisses. It can; but classically, it is valid if and only if the conclusion follows from a finite subset of them. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10977 | Compactness blocks the proof of 'for every n, A(n)' (as the proof would be infinite) [Read] |
| Full Idea: Compact consequence undergenerates - there are intuitively valid consequences which it marks as invalid, such as the ω-rule, that if A holds of the natural numbers, then 'for every n, A(n)', but the proof of that would be infinite, for each number. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10976 | Compactness makes consequence manageable, but restricts expressive power [Read] |
| Full Idea: Compactness is a virtue - it makes the consequence relation more manageable; but it is also a limitation - it limits the expressive power of the logic. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: The major limitation is that wholly infinite proofs are not permitted, as in Idea 10977. |
| 4229 | An infinite series of tasks can't be completed because it has no last member [Lowe] |
| Full Idea: It appears to be impossible to complete an infinite series of tasks, since such a series has, by definition, no last member. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.290) | |
| A reaction: This pinpoints the problem. So are there infinite tasks in a paradox of subdivision like the Achilles? |
| 11014 | Self-reference paradoxes seem to arise only when falsity is involved [Read] |
| Full Idea: It cannot be self-reference alone that is at fault. Rather, what seems to cause the problems in the paradoxes is the combination of self-reference with falsity. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.6) |
| 4240 | It might be argued that mathematics does not, or should not, aim at truth [Lowe] |
| Full Idea: It might be argued that mathematics does not, or should not, aim at truth. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.375) | |
| A reaction: Intriguing. Sounds wrong to me. At least maths seems to need the idea of the 'correct' answer. If, however, maths is a huge pattern, there is no correctness, just the pattern. We can be wrong, but maths can't be wrong. Ah, I see…! |
| 11025 | Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read] |
| Full Idea: Every potential infinity seems to suggest an actual infinity - e.g. generating successors suggests they are really all there already; cutting the line suggests that the point where the cut is made is already in place. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.8) | |
| A reaction: Finding a new gambit in chess suggests it was there waiting for us, but we obviously invented chess. Daft. |
| 10979 | Although second-order arithmetic is incomplete, it can fully model normal arithmetic [Read] |
| Full Idea: Second-order arithmetic is categorical - indeed, there is a single formula of second-order logic whose only model is the standard model ω, consisting of just the natural numbers, with all of arithmetic following. It is nevertheless incomplete. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: This is the main reason why second-order logic has a big fan club, despite the logic being incomplete (as well as the arithmetic). |
| 10980 | Second-order arithmetic covers all properties, ensuring categoricity [Read] |
| Full Idea: Second-order arithmetic can rule out the non-standard models (with non-standard numbers). Its induction axiom crucially refers to 'any' property, which gives the needed categoricity for the models. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) |
| 10997 | Von Neumann numbers are helpful, but don't correctly describe numbers [Read] |
| Full Idea: The Von Neumann numbers have a structural isomorphism to the natural numbers - each number is the set of all its predecessors, so 2 is the set of 0 and 1. This helps proofs, but is unacceptable. 2 is not a set with two members, or a member of 3. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) |
| 4241 | If there are infinite numbers and finite concrete objects, this implies that numbers are abstract objects [Lowe] |
| Full Idea: The Peano postulates imply an infinity of numbers, but there are probably not infinitely many concrete objects in existence, so natural numbers must be abstract objects. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.375) | |
| A reaction: Presumably they are abstract objects even if they aren't universals. 'Abstract' is an essential term in our ontological vocabulary to cover such cases. Perhaps possible concrete objects are infinite. |
| 4239 | Nominalists deny abstract objects, because we can have no reason to believe in their existence [Lowe] |
| Full Idea: Nominalists tend to deny the existence of abstract objects since, given their purported nature (non-causal), we can have no reason to believe in their existence. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.372) | |
| A reaction: A good point. Aristotle worried about the causal inadequacy of the Forms. My mind can conceive of a 'thing' with no causal powers, just sitting there. |
| 4202 | Change can be of composition (the component parts), or quality (properties), or substance [Lowe] |
| Full Idea: There seem to be three kinds of change: compositional change (of component parts), qualitative change (of properties), or substantial change (when underlying essence begins or ceases). | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.59) | |
| A reaction: Notice this gives 'components' a more prominent ontological status than usual. Is this computer a component of my study? |
| 4201 | Four theories of qualitative change are 'a is F now', or 'a is F-at-t', or 'a-at-t is F', or 'a is-at-t F' [Lowe, by PG] |
| Full Idea: Qualitative change is seen as either (i) 'Presentism' - 'a is F now', or (ii) 'relational properties' - 'a is F-at-t', or (iii) 'temporal parts' - 'a-at-t is F', or (iv) 'adverbial' - 'a is-a-t F'. | |
| From: report of E.J. Lowe (A Survey of Metaphysics [2002], p.44) by PG - Db (ideas) | |
| A reaction: The traditional view would let a stay the same over time, and change its property (ii). Lewis favours (iii). My suspicion is that thinking collapses if you abandon the tradtional view. |
| 4219 | Numerically distinct events of the same kind (like two battles) can coincide in space and time [Lowe] |
| Full Idea: Numerically distinct events of the same kind (like two battles) can plausible coincide in space and time. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.225) | |
| A reaction: This is certainly discouraging for anyone who wanted to make events ontologically basic. Physicalist need to be able to individuate events in a reductive way. |
| 4221 | Maybe modern physics requires an event-ontology, rather than a thing-ontology [Lowe] |
| Full Idea: It is sometimes said that modern physics requires us to espouse an event-ontology, rather than a thing-ontology. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.233) | |
| A reaction: It has to be a mistake to build our philosophical ontology on current physics, because even the physicists say they don't understand the latter very well. |
| 4220 | Maybe an event is the exemplification of a property at a time [Lowe] |
| Full Idea: Maybe an event is the exemplification of a property at a time. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.229) | |
| A reaction: What exactly would 'exemplify' mean here? This probably turns out to be circular when you attempt to explain what a property is. |
| 4225 | Events are changes in the properties of or relations between things [Lowe] |
| Full Idea: My own preference is for a conception of events which reduces them to changes in the properties of or relations between things. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.245) | |
| A reaction: Changes of property and changes of relations are two very different things. Is a 'near miss' an event? If so, is any movement an event? If movement is relative, then so are events. |
| 11016 | Would a language without vagueness be usable at all? [Read] |
| Full Idea: We must ask whether a language without vagueness would be usable at all. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) | |
| A reaction: Popper makes a similar remark somewhere, with which I heartily agreed. This is the idea of 'spreading the word' over the world, which seems the right way of understanding it. |
| 11019 | Supervaluations say there is a cut-off somewhere, but at no particular place [Read] |
| Full Idea: The supervaluation approach to vagueness is to construe vague predicates not as ones with fuzzy borderlines and no cut-off, but as having a cut-off somewhere, but in no particular place. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) | |
| A reaction: Presumably you narrow down the gap by supervaluation, then split the difference to get a definite value. |
| 11012 | A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read] |
| Full Idea: A 'supervaluation' says a proposition is true if it is true in all classical extensions of the original partial valuation. Thus 'A or not-A' has no valuation for an empty name, but if 'extended' to make A true or not-true, not-A always has opposite value. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) |
| 11013 | Identities and the Indiscernibility of Identicals don't work with supervaluations [Read] |
| Full Idea: In supervaluations, the Law of Identity has no value for empty names, and remains so if extended. The Indiscernibility of Identicals also fails if extending it for non-denoting terms, where Fa comes out true and Fb false. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) |
| 10700 | First- and second-order quantifiers are two ways of referring to the same things [Boolos] |
| Full Idea: Ontological commitment is carried by first-order quantifiers; a second-order quantifier needn't be taken to be a first-order quantifier in disguise, having special items, collections, as its range. They are two ways of referring to the same things. | |
| From: George Boolos (To be is to be the value of a variable.. [1984], p.72) | |
| A reaction: If second-order quantifiers are just a way of referring, then we can see first-order quantifiers that way too, so we could deny 'objects'. |
| 4196 | The main categories of existence are either universal and particular, or abstract and concrete [Lowe] |
| Full Idea: Some metaphysicians think the fundamental categories of existence are universals and particulars, while other prefer the division between abstract and concrete. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.15) | |
| A reaction: Interestingly, in trying to choose between these, it is tempting to think about the capacities of the brain. Which is the cart and which is the horse? |
| 4234 | Trope theory says blueness is a real feature of objects, but not the same as an identical blue found elsewhere [Lowe] |
| Full Idea: The trope theorist holds that the blueness of a blue chair really exists as much as the chair, but is not identified with the blueness of anything else, even if it resembles it exactly. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.361) | |
| A reaction: You are left with explaining how 'resemblance' works if you cannot spot some 'thing' in common. It is an inviting idea, though, because it avoids the ontological baggage of universals. |
| 4235 | Maybe a cushion is just a bundle of tropes, such as roundness, blueness and softness [Lowe] |
| Full Idea: The trope theorist says that a cushion is just a 'bundle' of tropes, such as roundness, blueness and softness. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.362) | |
| A reaction: Certainly if you dispense with the idea of substance (which is clearly bad science even if it is good metaphysics), something like this is what remains of a cushion, though it sounds more epistemological than ontological. Only philosophers care about this |
| 4236 | Tropes seem to be abstract entities, because they can't exist alone, but must come in bundles [Lowe] |
| Full Idea: Tropes seem to be abstract entities because, unlike concrete entities, they are ontologically dependent; ..there are no 'free' tropes, and they must always be bundled with other appropriate tropes to exist. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.367) | |
| A reaction: Only a Platonist would think that a universal property could 'exist alone'. I presume Aristotle thought universals were real, though bound up with substances. |
| 4197 | The category of universals can be sub-divided into properties and relations [Lowe] |
| Full Idea: One might want to divide the category of 'universals' into two sub-categories of properties and relations. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.15) | |
| A reaction: This means a Platonic form like 'horse' ends up as a cluster of properties and relations. Is a substance not also a universal? |
| 4232 | Nominalists believe that only particulars exist [Lowe] |
| Full Idea: Nominalists believe that only particulars exist. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.352) | |
| A reaction: A neat definition. Hence they deny universals. I suspect that nominalism is incoherent. Rational thought seems easy to create with universals, impossible with just particulars. Robotics is nominalist, which is why it will fail. |
| 4205 | 'Is non-self-exemplifying' is a predicate which cannot denote a property (as it would be a contradiction) [Lowe] |
| Full Idea: Not every meaningful predicate expresses an existing property; thus 'is non-self-exemplifying' cannot refer to a property, because the property would contradict the predicate. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.100) | |
| A reaction: Needs thought. The example is based on Russell's so-called Barber's Paradox. If it can't be a property, can it be a predicate? |
| 4233 | If 'blueness' is a set of particulars, there is danger of circularity, or using universals, in identifying the set [Lowe] |
| Full Idea: If sets are particulars, a nominalist may say that 'blueness' is a set of particulars, but which set? If the particulars 'are blue' this threatens circularity - though resemblance is usually appealed to to avoid this. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.355) | |
| A reaction: This supports my suspicion that nominalism is superficially attractive and 'scientific', but when you dig deep into it the theory won't get off the ground without universals. |
| 10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
| Full Idea: The haecceitist (a neologism coined by Duns Scotus, pronounced 'hex-ee-it-ist', meaning literally 'thisness') believes that each thing has an individual essence, a set of properties which are essential to it. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: This seems to be a difference of opinion over whether a haecceity is a set of essential properties, or a bare particular. The key point is that it is unique to each entity. |
| 4206 | Conventionalists see the world as an amorphous lump without identities, but are we part of the lump? [Lowe] |
| Full Idea: For the conventionalist the world is doomed to merge into an amorphous lump with no real individuality or differentiation, ..but we can hardly make our own identity in the world in the way we are supposed to conventionally create identity for objects. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.113) | |
| A reaction: Very nice argument! We need to 'cut nature at the joints' (Plato), and one joint is screamingly obvious - that between observer and world. You could try denying this, but it would be a bizarre view. |
| 4204 | Statues can't survive much change to their shape, unlike lumps of bronze, which must retain material [Lowe] |
| Full Idea: A statue is a kind of object which cannot survive much change to its shape, unlike a lump of bronze, which cannot survive any change to its material composition. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.70) | |
| A reaction: Also the statue could survive being hollowed out, changing its material composition. Hence a statue is not just a lump of bronze, but we knew that. |
| 4200 | If old parts are stored and then appropriated, they are no longer part of the original (which is the renovated ship). [Lowe] |
| Full Idea: The parts of a ship in a warehouse belong to no ship at all, ..and once they are appropriated by another ship they cease to be parts of the original, ..so it seems that the renovated ship (not the reconstruction) is identified with the original. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.31) | |
| A reaction: The parts in the warehouse could belong to the original (they might even labelled), but assigning them to a new ship does indeed look like a crucial break in the continuity. |
| 4198 | If 5% replacement preserves a ship, we can replace 4% and 4% again, and still retain the ship [Lowe] |
| Full Idea: If we say that up to 5% of a ship's parts can be replaced without the ship ceasing to exist, we could replace 4% and then 4% again, and it would retain its identity, if identity is transitive. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.26) | |
| A reaction: One suspected that all attempts at precision with the ship of Theseus were doomed, but this nicely demonstrates it. |
| 4199 | A renovation or a reconstruction of an original ship would be accepted, as long as the other one didn't exist [Lowe] |
| Full Idea: If a ship is renovated without reconstruction of original parts, we happily identify the renovation with the original; if there was a reconstruction without the renovated version, we would identify the reconstruction with the original. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.27) | |
| A reaction: This really shakes our belief in identity as a natural rather than mental phenomenon. The existence of clones undermines our normal idea of personal identity. |
| 4203 | Identity of Indiscernibles (same properties, same thing) ) is not Leibniz's Law (same thing, same properties) [Lowe] |
| Full Idea: The Identity of Indiscernibles (no two objects can possess exactly the same properties) is not the same as Leibniz's Law (what is true of a thing is true of what is identical with that thing). | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.62) | |
| A reaction: Two things can't be the same because we can't discern the difference, which may be our inadequacy. But if they actually have identical properties, it is hard to see how they could be different. A universe with just two perfect spheres is couterexample. |
| 11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
| Full Idea: The equation of 'necessity' with 'true in every possible world' is known as the S5 conception, corresponding to the strongest of C.I.Lewis's five modal systems. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: Are the worlds naturally, or metaphysically, or logically possible? |
| 4195 | It is impossible to reach a valid false conclusion from true premises, so reason itself depends on possibility [Lowe] |
| Full Idea: Reasoning itself depends upon a grasp of possibilities, because a valid argument is one in which it is not possible for the conclusion to be false if the premises are true. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.11) | |
| A reaction: A very valuable corrective to my pessimistic view of philosophers' attempts to understand metaphysical necessity. But if we can only grasp natural necessity, then all reason is naturalistic. |
| 10989 | The standard view of conditionals is that they are truth-functional [Read] |
| Full Idea: The standard view of conditionals is that they are truth-functional, that is, that their truth-values are determined by the truth-values of their constituents. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.3) |
| 11017 | Some people even claim that conditionals do not express propositions [Read] |
| Full Idea: Some people even claim that conditionals do not express propositions. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.7) | |
| A reaction: See Idea 14283, where this appears to have been 'proved' by Lewis, and is not just a view held by some people. |
| 10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
| Full Idea: The point of conditionals is to show that one will accept modus ponens. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.3) | |
| A reaction: [He attributes this idea to Frank Jackson] This makes the point, against Grice, that the implication of conditionals is not conversational but a matter of logical convention. See Idea 21396 for a very different view. |
| 4207 | We might eliminate 'possible' and 'necessary' in favour of quantification over possible worlds [Lowe] |
| Full Idea: It may be possible to eliminate the modal operators (in English, 'is possible' and 'is necessary') in favour of quantifier expressions with variables ranging over possible worlds. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.121) | |
| A reaction: Hence 'necessary' becomes 'exists/is true in all possible worlds'. Deep problems, but at least we must show that referring to 'possible' worlds isn't a circular explanation of 'is possible'. |
| 10983 | Knowledge of possible worlds is not causal, but is an ontology entailed by semantics [Read] |
| Full Idea: The modal Platonist denies that knowledge always depends on a causal relation. The reality of possible worlds is an ontological requirement, to secure the truth-values of modal propositions. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: [Reply to Idea 10982] This seems to be a case of deriving your metaphyics from your semantics, of which David Lewis seems to be guilty, and which strikes me as misguided. |
| 10982 | How can modal Platonists know the truth of a modal proposition? [Read] |
| Full Idea: If modal Platonism was true, how could we ever know the truth of a modal proposition? | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: I take this to be very important. Our knowledge of modal truths must depend on our knowledge of the actual world. The best answer seems to involve reference to the 'powers' of the actual world. A reply is in Idea 10983. |
| 10996 | Actualism is reductionist (to parts of actuality), or moderate realist (accepting real abstractions) [Read] |
| Full Idea: There are two main forms of actualism: reductionism, which seeks to construct possible worlds out of some more mundane material; and moderate realism, in which the actual concrete world is contrasted with abstract, but none the less real, possible worlds. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: I am a reductionist, as I do not take abstractions to be 'real' (precisely because they have been 'abstracted' from the things that are real). I think I will call myself a 'scientific modalist' - we build worlds from possibilities, discovered by science. |
| 10981 | A possible world is a determination of the truth-values of all propositions of a domain [Read] |
| Full Idea: A possible world is a complete determination of the truth-values of all propositions over a certain domain. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.2) | |
| A reaction: Even if the domain is very small? Even if the world fitted the logic nicely, but was naturally impossible? |
| 11000 | If worlds are concrete, objects can't be present in more than one, and can only have counterparts [Read] |
| Full Idea: If each possible world constitutes a concrete reality, then no object can be present in more than one world - objects may have 'counterparts', but cannot be identical with them. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: This explains clearly why in Lewis's modal realist scheme he needs counterparts instead of rigid designation. Sounds like a slippery slope. If you say 'Humphrey might have won the election', who are you talking about? |
| 4223 | Unfalsifiability may be a failure in an empirical theory, but it is a virtue in metaphysics [Lowe] |
| Full Idea: Although unfalsifiability is probably a defect in scientific hypothesis, because it is deprived of empirical content, it seems rather to be a virtue in a metaphysical hypothesis. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.241) | |
| A reaction: Presumably nothing could ever be found to count against a necessary truth. A nice point. 'Find me an instance where 2+2 is not 4'. |
| 4193 | The behaviour of persons and social groups seems to need rational rather than causal explanation [Lowe] |
| Full Idea: There are some entities which exist in time and space (such as persons or social groups) of which the behaviour seems to be subject to rational rather than merely causal explanation. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.2) | |
| A reaction: This begs of the question of whether 'rational' can be reduced to causal. We can't manage causal explanations of the very complex, so we use broad-brush second-best explanations? |
| 10998 | The mind abstracts ways things might be, which are nonetheless real [Read] |
| Full Idea: Ways things might be are real, but only when abstracted from the actual way things are. They are brought out and distinguished by the mind, by abstraction, but are not dependent on mind for their existence. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.4) | |
| A reaction: To me this just flatly contradicts itself. The idea that the mind can 'bring something out' by its operations, with the result being then accepted as part of reality is nonsense on stilts. What is real is the powers that make the possibilities. |
| 4238 | The centre of mass of the solar system is a non-causal abstract object, despite having a location [Lowe] |
| Full Idea: The centre of mass of the solar system seems to lack causal powers, and so is an abstract object, even though it has a location and movement. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.368) | |
| A reaction: Nice example, with rich ramifications. Abstraction is deeply tied into our understanding of the physical world, and our concept of identity. |
| 4237 | Concrete and abstract objects are distinct because the former have causal powers and relations [Lowe] |
| Full Idea: Concrete objects possess causal powers and relations, but abstract objects are incapable of having causal powers or relations. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.368) | |
| A reaction: Is this an observation or a definition? One might claim that an abstraction (such as a political ideal) can acquire causal power through a conscious mnd. |
| 11005 | Negative existentials with compositionality make the whole sentence meaningless [Read] |
| Full Idea: A problem with compositionality is negative existential propositions. If some of the terms of the proposition are empty, and don't refer, then compositionality implies that the whole will lack meaning too. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.5) | |
| A reaction: I don't agree. I don't see why compositionality implies holism about sentence-meaning. If I say 'that circular square is a psychopath', you understand the predication, despite being puzzled by the singular term. |
| 10966 | A proposition objectifies what a sentence says, as indicative, with secure references [Read] |
| Full Idea: A proposition makes an object out of what is said or expressed by the utterance of a certain sort of sentence, namely, one in the indicative mood which makes sense and doesn't fail in its references. It can then be an object of thought and belief. | |
| From: Stephen Read (Thinking About Logic [1995], Ch.1) | |
| A reaction: Nice, but two objections: I take it to be crucial to propositions that they eliminate ambiguities, and I take it that animals are capable of forming propositions. Read seems to regard them as fictions, but I take them to be brain events. |
| 4210 | If the concept of a cause says it precedes its effect, that rules out backward causation by definition [Lowe] |
| Full Idea: You can't include in your concept of causation a clause stipulating that the cause occurred earlier than the effect, because that would rule out backward causation by definition. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.176) | |
| A reaction: It may, though, be the case that backward causes can't occur, and time is essential to causes. The problem is our inability to know this for sure. |
| 4215 | It seems proper to say that only substances (rather than events) have causal powers [Lowe] |
| Full Idea: It seems proper to say that events of themselves possess no causal powers; only persisting objects (individual substances) possess causal powers. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.211) | |
| A reaction: This requires events to be reduced to substances, which invites Aristotle's question of where the movement comes from. In physcis, 'energy' is the key concept. |
| 4209 | The theories of fact causation and event causation are both worth serious consideration [Lowe] |
| Full Idea: The theories of fact causation and event causation are both worth serious consideration. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.173) | |
| A reaction: This is slippery ground because both 'facts' and 'events' have uncertain ontological status, and seem partly conventional rather than natural. Events might be natural surges or transformations of energy? |
| 4211 | Causal overdetermination is either actual overdetermination, or pre-emption, or the fail-safe case [Lowe] |
| Full Idea: In causation there is 'overdetermination' (c and d occurred, and were both sufficient for e), 'pre-emption' (c and d occurred, and d would have stepped in if c hadn't), or 'fail-safe' (if c hadn't occurred, d would have occurred and done it). | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.179) | |
| A reaction: Two safety nets together, two safety nets spaced apart, or a second net which pops in if the first breaks. Nice distinctions. |
| 4213 | Causation may be instances of laws (seen either as constant conjunctions, or as necessities) [Lowe] |
| Full Idea: Causation relations between events may an instance of a causal law, with laws either interpreted as constant conjunctions (Hume), or as necessitation among universals (Armstrong). | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.190) | |
| A reaction: Hume's version is a thin idea of a law, but we can dream about the metaphysical status of laws, even if we don't know much about them. Lowe says a cause without a law is perfectly intelligible. |
| 4212 | Hume showed that causation could at most be natural necessity, never metaphysical necessity [Lowe] |
| Full Idea: One thing Hume has taught us is that the necessity which causation involves is at most 'natural' or 'physical' necessity, not metaphysical necessity. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.182) | |
| A reaction: Given Hume's epistemological scepticism, I don't think he would claim to have shown such a thing. See G.Strawson's book. Metaphysical necessity of causation is possible, but unknowable. |
| 14581 | The normative view says laws show the natural behaviour of natural kind members [Lowe, by Mumford/Anjum] |
| Full Idea: For Lowe law statements are in a sense about what 'ought' to be the case. The 'ought' is not an explicitly moral or anthropomorphic one but instead tells us what is the natural behaviour of kind members. | |
| From: report of E.J. Lowe (A Survey of Metaphysics [2002]) by S.Mumford/R.Lill Anjum - Getting Causes from Powers 8.6 | |
| A reaction: This is the 'normative' view of laws (as opposed to the intentional, dispositional, or regularity accounts). They cite Lowe 1989 Ch.8. The obvious immediate problem is things which evolved for one purpose and end up being used for another. |
| 4208 | 'If he wasn't born he wouldn't have died' doesn't mean birth causes death, so causation isn't counterfactual [Lowe] |
| Full Idea: Counterfactual analyses of event causation don't seem to work, because 'if Napoleon hadn't been born he wouldn't have died' is true, but doesn't mean his birth caused his death. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.161) | |
| A reaction: Nice counterexample, which looks pretty conclusive. Birth makes death possible; it creates the necessary conditions within which it can be caused. |
| 4224 | If motion is change of distance between objects, it involves no intrinsic change in the objects [Lowe] |
| Full Idea: If motion just is change of distance between two objects, it does not involve any kind of intrinsic change in the objects in question. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.242) | |
| A reaction: It sound respectably relativistic, but I doubt the definition. x is moving relative to y, then y attains x's velocity, so x ceases to move? Maybe. |
| 4227 | Surfaces, lines and points are not, strictly speaking, parts of space, but 'limits', which are abstract [Lowe] |
| Full Idea: Surfaces, lines and points are not, strictly speaking, parts of space at all, but just 'limits' of certain kinds, and as such 'abstract' entities. | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.254) | |
| A reaction: This is fairly crucial when dealing with Zeno's paradoxes. How many points in a line? How long to get through a point? |
| 4228 | If space is entirely relational, what makes a boundary, or a place unoccupied by physical objects? [Lowe] |
| Full Idea: If space does not exist at all, but is only relations between objects, what could one possibly mean by saying that there is a place which is unoccupied by any material object? And what determines whether space is bounded? | |
| From: E.J. Lowe (A Survey of Metaphysics [2002], p.264) | |
| A reaction: Correct. People who assert that space is only relational have been misled by what we can know about space, not what it is. |