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All the ideas for 'From an Ontological Point of View', 'Aquinas, Thomas' and 'Parts of Classes'

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90 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
If you begin philosophy with language, you find yourself trapped in it [Heil]
     Full Idea: If you start with language and try to work your way outwards, you will never get outside language.
     From: John Heil (From an Ontological Point of View [2003], Pref)
     A reaction: This voices my pessimism about the linguistic approach to philosophy (and I don't just mean analysis of ordinary language), though I wonder if the career of (say) John Searle is a counterexample.
2. Reason / B. Laws of Thought / 6. Ockham's Razor
A theory with few fundamental principles might still posit a lot of entities [Heil]
     Full Idea: It could well turn out that a simpler theory - a theory with fewer fundamental principles - posits more entities than a more complex competitor.
     From: John Heil (From an Ontological Point of View [2003], 13.6)
     A reaction: See also Idea 4036. The point here is that you can't simply translate Ockham as 'keep it simple', as there are different types of simplicity. The best theory will negotiate a balance between entities and principles.
Parsimony does not imply the world is simple, but that our theories should try to be [Heil]
     Full Idea: A commitment to parsimony is not a commitment to a conception of the world as simple. The idea, rather, is that we should not complicate our theories about the world unnecessarily.
     From: John Heil (From an Ontological Point of View [2003], 13.6)
     A reaction: In other words, Ockham's Razor is about us, not about the world. It would be absurd to make the a priori assumption that the world has to be simple. Are we, though, creating bad theories by insisting that they should be simple?
3. Truth / B. Truthmakers / 4. Truthmaker Necessitarianism
The view that truth making is entailment is misguided and misleading [Heil]
     Full Idea: I argue that the widely held view that truth making is to be understood as entailment is misguided in principle and potentially misleading.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: If reality was just one particle, what would entail the truths about it? Suppose something appears to be self-evident true about reality, but no one can think of any entailments to derive it? Do we assume a priori that they are possible?
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Sets are mereological sums of the singletons of their members [Lewis, by Armstrong]
     Full Idea: Lewis pointed out that many-membered classes are nothing more than the mereological wholes of the classes formed by taking the singleton of each member.
     From: report of David Lewis (Parts of Classes [1991]) by David M. Armstrong - Truth and Truthmakers 09.4
     A reaction: You can't combine members to make the class, because the whole and the parts are of different type, but here the parts and whole are both sets, so they combine like waterdrops.
We can build set theory on singletons: classes are then fusions of subclasses, membership is the singleton [Lewis]
     Full Idea: The notion of a singleton, or unit set, can serve as the distinctive primitive of set theory. The rest is mereology: a class is the fusion of its singleton subclasses, something is a member of a class iff its singleton is part of that class.
     From: David Lewis (Parts of Classes [1991], Pref)
     A reaction: This is a gloriously bold proposal which I immediately like, because it cuts out the baffling empty set (which many people think 'exists'!), and gets mathematics back to being about the real world of entities (as the Greeks thought).
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
Classes divide into subclasses in many ways, but into members in only one way [Lewis]
     Full Idea: A class divides exhaustively into subclasses in many different ways; whereas a class divides exhaustively into members in only one way.
     From: David Lewis (Parts of Classes [1991], 1.2)
A subclass of a subclass is itself a subclass; a member of a member is not in general a member [Lewis]
     Full Idea: Just as a part of a part is itself a part, so a subclass of a subclass is itself a subclass; whereas a member of a member is not in general a member.
     From: David Lewis (Parts of Classes [1991], 1.2)
     A reaction: Lewis is showing the mereological character of sets, but this is a key distinction in basic set theory. When the members of members are themselves members, the set is said to be 'transitive'.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
We needn't accept this speck of nothingness, this black hole in the fabric of Reality! [Lewis]
     Full Idea: Must we accept the null set as a most extraordinary individual, a little speck of sheer nothingness, a sort of black hole in the fabric of Reality itself? Not really.
     From: David Lewis (Parts of Classes [1991], 1.4)
     A reaction: We can only dream of reaching the level of confidence that Lewis reached, to make such beautiful fun of a highly counterintuitive idea that is rooted in the modern techniques of philosophy.
We can accept the null set, but there is no null class of anything [Lewis]
     Full Idea: There is no such class as the null class. I don't mind calling some memberless thing - some individual - the null 'set'. But that doesn't make it a memberless class.
     From: David Lewis (Parts of Classes [1991], 1.2)
     A reaction: The point is that set theory is a formal system which can do what it likes, but classes are classes 'of' things. Everyone assumes that sets are classes, reserving 'proper classes' for the tricky cases up at the far end.
There are four main reasons for asserting that there is an empty set [Lewis]
     Full Idea: The null set is a denotation of last resort for class-terms that fail to denote classes, an intersection of x and y where they have no members in common, the class of all self-members, and the real numbers such that x^2+1=0. This is all mere convenience.
     From: David Lewis (Parts of Classes [1991], 1.4)
     A reaction: A helpful catalogue of main motivations for the existence of the null set in set theory. Lewis aims to undermine these reasons, and dispense with the wretched thing.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
If we don't understand the singleton, then we don't understand classes [Lewis]
     Full Idea: Our utter ignorance about the nature of the singletons amounts to sheer ignorance about the nature of classes generally.
     From: David Lewis (Parts of Classes [1991], 2.1)
We can replace the membership relation with the member-singleton relation (plus mereology) [Lewis]
     Full Idea: Given the theory of part and whole, the member-singleton relation may replace membership generally as the primitive notion of set theory.
     From: David Lewis (Parts of Classes [1991], Pref)
     A reaction: An obvious question is to ask what the member-singleton relation is if it isn't membership.
If singleton membership is external, why is an object a member of one rather than another? [Lewis]
     Full Idea: Suppose the relation of member to singleton is external. Why must Possum be a member of one singleton rather than another? Why isn't it contingent which singleton is his?
     From: David Lewis (Parts of Classes [1991], 2.2)
     A reaction: He cites Van Inwagen for raising this question, and answers it in terms of counterparts. So is the relation internal or external? I think of sets as pairs of curly brackets, not existing entities, so the question doesn't bother me.
Maybe singletons have a structure, of a thing and a lasso? [Lewis]
     Full Idea: Maybe the singleton of something x is not an atom, but consists of x plus a lasso. That gives a singleton an internal structure. ...But what do we know of the nature of the lasso, or how it fits? We are no better off.
     From: David Lewis (Parts of Classes [1991], 2.5)
     A reaction: [second bit on p.45]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Set theory has some unofficial axioms, generalisations about how to understand it [Lewis]
     Full Idea: Set theory has its unofficial axioms, traditional remarks about the nature of classes. They are never argued, but are passed heedlessly from one author to another. One of these says that the classes are nowhere: they are outside space and time.
     From: David Lewis (Parts of Classes [1991], 2.1)
     A reaction: Why don't the people who write formal books on set theory ever say things like this?
Set theory reduces to a mereological theory with singletons as the only atoms [Lewis, by MacBride]
     Full Idea: Lewis has shown that set theory may be reduced to a mereological theory in which singletons are the only atoms.
     From: report of David Lewis (Parts of Classes [1991]) by Fraser MacBride - Review of Chihara's 'Structural Acc of Maths' p.80
     A reaction: Presumably the axiom of extensionality, that a set is no more than its members, translates into unrestricted composition, that any parts will make an object. Difficult territory, but I suspect that this is of great importance in metaphysics.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
If singletons are where their members are, then so are all sets [Lewis]
     Full Idea: If every singleton was where its member was, then, in general, classes would be where there members were.
     From: David Lewis (Parts of Classes [1991], 2.1)
     A reaction: There seems to be a big dislocation of understanding of the nature of sets, between 'pure' set theory, and set theory with ur-elements. I take the pure to be just an 'abstraction' from the more located one. The empty set has a puzzling location.
A huge part of Reality is only accepted as existing if you have accepted set theory [Lewis]
     Full Idea: The preponderant part of Reality must consist of unfamiliar, unobserved things, whose existence would have gone unsuspected but for our acceptance of set theory.
     From: David Lewis (Parts of Classes [1991], 2.6)
     A reaction: He is referring to the enormous sets at the far end of set theory, of a size that had never been hitherto conceived. Excellent. Daft to believe in something entirely because you have accepted set theory, with no other basis.
Set theory isn't innocent; it generates infinities from a single thing; but mathematics needs it [Lewis]
     Full Idea: Set theory is not innocent. Its trouble is that when we have one thing, then somehow we have another wholly distinct thing, the singleton. And another, and another....ad infinitum. But that's the price for mathematical power. Pay it.
     From: David Lewis (Parts of Classes [1991], 3.6)
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
God does not create the world, and then add the classes [Heil]
     Full Idea: It is hard to see classes as an 'addition of being'; God does not create the world, and then add the classes.
     From: John Heil (From an Ontological Point of View [2003], 13.4 n6)
     A reaction: This seems right. We may be tempted into believing in the reality of classes when considering maths, but it seems utterly implausible when considering trees or cows.
5. Theory of Logic / G. Quantification / 6. Plural Quantification
Plural quantification lacks a complete axiom system [Lewis]
     Full Idea: There is an irremediable lack of a complete axiom system for plural quantification.
     From: David Lewis (Parts of Classes [1991], 4.7)
I like plural quantification, but am not convinced of its connection with second-order logic [Lewis]
     Full Idea: I agree fully with Boolos on substantive questions about plural quantification, though I would make less than he does of the connection with second-order logic.
     From: David Lewis (Parts of Classes [1991], 3.2 n2)
     A reaction: Deep matters, but my inclination is to agree with Lewis, as I have never been able to see why talk of plural quantification led straight on to second-order logic. A plural is just some objects, not some higher-order entity.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
Zermelo's model of arithmetic is distinctive because it rests on a primitive of set theory [Lewis]
     Full Idea: What sets Zermelo's modelling of arithmetic apart from von Neumann's and all the rest is that he identifies the primitive of arithmetic with an appropriately primitive notion of set theory.
     From: David Lewis (Parts of Classes [1991], 4.6)
     A reaction: Zermelo's model is just endlessly nested empty sets, which is a very simple structure. I gather that connoisseurs seem to prefer von Neumann's model (where each number contains its predecessor number).
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Giving up classes means giving up successful mathematics because of dubious philosophy [Lewis]
     Full Idea: Renouncing classes means rejecting mathematics. That will not do. Mathematics is an established, going concern. Philosophy is as shaky as can be.
     From: David Lewis (Parts of Classes [1991], 2.8)
     A reaction: This culminates in his famous 'Who's going to tell the mathematicians? Not me!'. He has just given four examples of mathematics that seems to entirely depend on classes. This idea sounds like G.E. Moore's common sense against scepticism.
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
To be a structuralist, you quantify over relations [Lewis]
     Full Idea: To be a structuralist, you quantify over relations.
     From: David Lewis (Parts of Classes [1991], 2.6)
7. Existence / A. Nature of Existence / 2. Types of Existence
Existence doesn't come in degrees; once asserted, it can't then be qualified [Lewis]
     Full Idea: Existence cannot be a matter of degree. If you say there is something that exists to a diminished degree, once you've said 'there is' your game is up.
     From: David Lewis (Parts of Classes [1991], 3.5)
     A reaction: You might have thought that this was so obvious as to be not worth saying, but as far as I can see it is a minority view in contemporary philosophy. It was Quine's view, and it is mine.
7. Existence / C. Structure of Existence / 2. Reduction
The reductionist programme dispenses with levels of reality [Heil]
     Full Idea: The reductionist programme dispenses with levels of reality.
     From: John Heil (From an Ontological Point of View [2003], 04.3)
     A reaction: Fodor, for example, claims that certain causal laws only operate at high levels of reality. I agree with Heil's idea - the notion that there are different realities around here that don't connect properly to one another is philosopher's madness.
7. Existence / C. Structure of Existence / 3. Levels of Reality
There are levels of organisation, complexity, description and explanation, but not of reality [Heil]
     Full Idea: We should accept levels of organisation, levels of complexity, levels of description, and levels of explanation, but not the levels of reality favoured by many anti-reductionists. The world is then ontologically, but not analytically, reductive.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: This sounds right to me. The crunch questions seem to be whether the boundaries at higher levels of organisation exist lower down, and whether the causal laws of the higher levels can be translated without remainder into lower level laws.
7. Existence / C. Structure of Existence / 8. Stuff / a. Pure stuff
We have no idea of a third sort of thing, that isn't an individual, a class, or their mixture [Lewis]
     Full Idea: As yet we have no idea of any third sort of thing that is neither individual nor class nor mixture of the two.
     From: David Lewis (Parts of Classes [1991], 1.2)
     A reaction: You can see that Lewis was a pupil of Quine. I quote this to show how little impression 'stuff' makes on the modern radar. His defence is that stuff may not be a 'thing', but then he seems to think that 'things' exhaust reality (top p.8 and 9).
Atomless gunk is an individual whose parts all have further proper parts [Lewis]
     Full Idea: A blob can represent atomless gunk: an individual whose parts all have further proper parts.
     From: David Lewis (Parts of Classes [1991], 1.8)
     A reaction: This is not the same as 'stuff', since gunk is a precise fusion of all those parts, whereas there is no such precision about stuff. Stuff is neutral as to whether it has atoms, or is endlessly divisible. My love of stuff grows. Laycock is a hero.
7. Existence / D. Theories of Reality / 2. Realism
Realism says some of our concepts 'cut nature at the joints' [Heil]
     Full Idea: Realism is sometimes said to involve a commitment to the idea that certain of our concepts, those with respect to which we are realists, 'carve reality at the joints'.
     From: John Heil (From an Ontological Point of View [2003], 14.11)
     A reaction: Clearly not all concepts cut nature at the joints (e.g. we have concepts of things we know to be imaginary). Personally I am committed to this view of realism. I try very hard to use concepts that cut accurately; why shouldn't I sometimes succeed?
7. Existence / D. Theories of Reality / 4. Anti-realism
Anti-realists who reduce reality to language must explain the existence of language [Heil]
     Full Idea: Anti-realist philosophers, and those who hope to reduce metaphysics to (or replace it with) the philosophy of language, owe the rest of us an account of the ontology of language.
     From: John Heil (From an Ontological Point of View [2003], 20.6)
     A reaction: A nice turning-the-tables question. In all accounts of relativism, x is usually said to be relative to y. You haven't got proper relativism if you haven't relativised both x and y. But relativised them to what? Nietzsche's 'perspectivism' (Idea 4420)?
7. Existence / E. Categories / 5. Category Anti-Realism
Concepts don't carve up the world, which has endless overlooked or ignored divisions [Heil]
     Full Idea: Concepts do not 'carve up' the world; the world already contains endless divisions, most of which we remain oblivious to or ignore.
     From: John Heil (From an Ontological Point of View [2003], 05.3)
     A reaction: Concepts could still carve up the world, without ever aspiring to do a complete job. We carve up the aspects that interest us, but the majority of the carving is in response to natural divisions, not whimsical conventions.
8. Modes of Existence / B. Properties / 9. Qualities
I think of properties as simultaneously dispositional and qualitative [Heil]
     Full Idea: Some philosophers who accept that properties are intrinsic features of objects regard them as pure powers, pure dispositionalities; I prefer to think of properties as simultaneously dispositional and qualitative.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: I am uneasy about 'qualitative' as a category, and am inclined to reduce it to being a dispositional power to cause primary and secondary qualities in observers. Roughness is only a power, not a quality, if there are no observers.
8. Modes of Existence / B. Properties / 10. Properties as Predicates
A predicate applies truly if it picks out a real property of objects [Heil]
     Full Idea: When a predicate applies truly to an object, it does so in virtue of designating a property possessed by that object and by every object to which the predicate truly applies (or would apply).
     From: John Heil (From an Ontological Point of View [2003], 03.3)
     A reaction: I am sympathetic to Heil's aim of shifting our attention from arbitrary predicates to natural properties, but it won't avoid Fodor's problem (Idea 7014) that all kinds of whimsical predicates will apply 'truly', but fail to pick out anything significant.
8. Modes of Existence / B. Properties / 11. Properties as Sets
A property is any class of possibilia [Lewis]
     Full Idea: A property is any class of possibilia.
     From: David Lewis (Parts of Classes [1991], 2.7)
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
A theory of universals says similarity is identity of parts; for modes, similarity is primitive [Heil]
     Full Idea: The friend of universals has an account of similarity relations as relations of identity and partial identity; the friend of modes must regard similarity relations as primitive and irreducible.
     From: John Heil (From an Ontological Point of View [2003], 14.5)
     A reaction: We always seem to be able to ask 'in what respect' a similarity occurs. If similarity is 'primitive and irreducible', we should not be able to analyse and explain a similarity, yet we seem able to. I conclude that Heil is wrong.
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
Powers or dispositions are usually seen as caused by lower-level qualities [Heil]
     Full Idea: The modern default position on dispositionality is that powers or dispositions are higher-level properties objects possess by virtue of those objects' possession of lower-level qualitative (categorical) properties.
     From: John Heil (From an Ontological Point of View [2003], 09.2)
     A reaction: The new idea which is being floated by Heil, and which I prefer, is that dispositions or powers are basic. A 'quality' is a much more dubious entity than a power.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Are a property's dispositions built in, or contingently added? [Heil]
     Full Idea: There is a dispute over whether a property's dispositionality is built into the property or whether it is a contingent add-on.
     From: John Heil (From an Ontological Point of View [2003], 09.4)
     A reaction: Put that way, the idea that it is built in seems much more plausible. If it is an add-on, an explanation of why that disposition is added to that particular property seems required. If it is built in, it seems legitimate to accept it as a brute fact.
8. Modes of Existence / D. Universals / 2. Need for Universals
Universals explain one-over-many relations, and similar qualities, and similar behaviour [Heil]
     Full Idea: Universals can explain the one-over-many problem, and easily explain similarity relations between objects, and explain the similar behaviour of similar objects.
     From: John Heil (From an Ontological Point of View [2003], 13.1)
     A reaction: A useful summary. If you accept it, you seem to be faced with a choice between Plato (who has universals existing independently of particulars) and Armstrong (who makes them real, but existing only in particulars).
8. Modes of Existence / D. Universals / 6. Platonic Forms / d. Forms critiques
How could you tell if the universals were missing from a world of instances? [Heil]
     Full Idea: Imagine a pair of worlds, one in which there are the universals and their instances and one in which there are just the instances (a world of modes). How would the absence of universals make itself felt?
     From: John Heil (From an Ontological Point of View [2003], 13.7)
     A reaction: A nice question for Plato, very much in the spirit of Aristotle's string of questions. Compare 'suppose the physics remained, but someone removed the laws'. Either chaos ensues, or you realise they were redundant. Same with Forms.
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Similarity among modes will explain everthing universals were for [Heil]
     Full Idea: My contention is that similarity among modes can do the job universals are conventionally postulated to do.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: See Idea 4441 for Russell's nice objection to this view. The very process by which we observes similarities (as assess their degrees) needs to be explained by any adequate theory of properties or universals.
Similar objects have similar properties; properties are directly similar [Heil]
     Full Idea: Objects are similar by virtue of possessing similar properties; properties, in contrast, are not similar in virtue of anything.
     From: John Heil (From an Ontological Point of View [2003], 14.2)
     A reaction: I am not sure if I can understand the concept of similarity if there is no answer to the question 'In what respect?' I suppose David Hume is happy to take resemblance as given and basic, but it could be defined as 'sharing identical properties'.
8. Modes of Existence / E. Nominalism / 5. Class Nominalism
Objects join sets because of properties; the property is not bestowed by set membership [Heil]
     Full Idea: The set of red objects is the set of objects possessing a property: being red. Objects are members of the set in virtue of possessing this property; they do not possess the property in virtue of belonging to the set.
     From: John Heil (From an Ontological Point of View [2003], 12.2)
     A reaction: This seems to be a very effective denial of the claim that universals are sets. However, if 'being a Londoner' counts as a property, you can only have it by joining the London set. Being tall is more fundamental than being a Londoner.
9. Objects / A. Existence of Objects / 1. Physical Objects
Trope theorists usually see objects as 'bundles' of tropes [Heil]
     Full Idea: Philosophers identifying themselves as trope theorists have, by and large, accepted some form of the 'bundle theory' of objects: an object is a bundle of compresent tropes.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: This view eliminates anything called 'matter' or 'substance' or a 'bare particular'. I think I agree with Heil that this doesn't give a coherent picture, as properties seem to be 'of' something, and bundles always raise the question of what unites them.
Objects are substances, which are objects considered as the bearer of properties [Heil]
     Full Idea: I think of objects as substances, and a substance is an object considered as a bearer of properties.
     From: John Heil (From an Ontological Point of View [2003], 04.2)
     A reaction: This is an area of philosophy I always find disconcerting, where an account of how we should see objects seems to have no connection at all to what physicists report about objects. 'Considered as' seems to make substances entirely conventional.
9. Objects / B. Unity of Objects / 2. Substance / c. Types of substance
Maybe there is only one substance, space-time or a quantum field [Heil]
     Full Idea: It would seem distinctly possible that there is but a single substance: space-time or some all-encompassing quantum field.
     From: John Heil (From an Ontological Point of View [2003], 05.2)
     A reaction: This would at least meet my concern that philosophers' 'substances' don't seem to connect to what physicists talk about. I wonder if anyone knows what a 'quantum field' is? The clash between relativity and quantum theory is being alluded to.
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
Rather than 'substance' I use 'objects', which have properties [Heil]
     Full Idea: I prefer the more colloquial 'object' to the traditional term 'substance'. An object can be regarded as a possessor of properties: as something that is red, spherical and pungent, for instance.
     From: John Heil (From an Ontological Point of View [2003], 15.3)
     A reaction: A nice move, but it seems to beg the question of 'what is it that has the properties?' Objects and substances do two different jobs in our ontology. Heil is just refusing to discuss what it is that has properties.
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
Statues and bronze lumps have discernible differences, so can't be identical [Heil]
     Full Idea: Applications of the principle of the indiscernibility of identicals apparently obliges us to distinguish the statue and the lump of bronze making it up.
     From: John Heil (From an Ontological Point of View [2003], 16.3)
     A reaction: In other words, statues and lumps of bronze have different properties. It is a moot point, though, whether there are any discernible differences between that statue at time t and its constituting lump of bronze at time t.
Do we reduce statues to bronze, or eliminate statues, or allow statues and bronze? [Heil]
     Full Idea: Must we choose between reductionism (the statue is the lump of bronze), eliminativism (there are no statues, only statue-shaped lumps of bronze), and a commitment to coincident objects?
     From: John Heil (From an Ontological Point of View [2003], 16.5)
     A reaction: (Heil goes on to offer his own view). Coincident objects sounds the least plausible view. Modern statues are only statues if we see them that way, but a tree is definitely a tree. Trenton Merricks is good on eliminativism.
9. Objects / C. Structure of Objects / 5. Composition of an Object
The many are many and the one is one, so they can't be identical [Lewis]
     Full Idea: What is true of the many is not exactly what is true of the one. After all they are many while it is one. The number of the many is six, whereas the number of the fusion is one. The singletons of the many are distinct from the singleton of the one.
     From: David Lewis (Parts of Classes [1991], 3.6)
     A reaction: I wouldn't take this objection to be conclusive. 'Some pebbles' seem to be many, but a 'handful of pebbles' seem to be one, where the physical situation might be identical. If they are not identical, then the non-identity is purely conceptual.
Lewis affirms 'composition as identity' - that an object is no more than its parts [Lewis, by Merricks]
     Full Idea: Lewis says that the parts of a thing are identical with the whole they compose, calling his view 'composition as identity', which is the claim that a physical object is 'nothing over and above its parts'.
     From: report of David Lewis (Parts of Classes [1991], p.84-7) by Trenton Merricks - Objects and Persons §I.IV
     A reaction: The ontological economy of this view is obviously attractive, but I don't agree with it. You certainly can't say that all identity consists entirely of composition by parts, because the parts need identity to get the view off the ground.
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
In mereology no two things consist of the same atoms [Lewis]
     Full Idea: It is a principle of mereology that no two things consist of exactly the same atoms.
     From: David Lewis (Parts of Classes [1991], 2.3)
     A reaction: The problem with this is screamingly obvious - that the same atoms might differ in structure. Lewis did refer to this problem, but seems to try to wriggle out of it, in Idea 15444.
Trout-turkeys exist, despite lacking cohesion, natural joints and united causal power [Lewis]
     Full Idea: A trout-turkey is inhomogeneous, disconnected, not in contrast with its surroundings. It is not cohesive, not causally integrated, not a causal unit in its impact on the rest of the world. It is not carved at the joints. That doesn't affect its existence.
     From: David Lewis (Parts of Classes [1991], 3.5)
     A reaction: A nice pre-emptive strike against all the reasons why anyone might think more is needed for unity than a mereological fusion.
Given cats, a fusion of cats adds nothing further to reality [Lewis]
     Full Idea: Given a prior commitment to cats, a commitment to cat-fusions is not a further commitment. The fusion is nothing over and above the cats that compose it. It just is them. They just are it. Together or separately, the cats are the same portion of Reality.
     From: David Lewis (Parts of Classes [1991], 3.6)
     A reaction: The two extremes of ontology are that there are no objects, or that every combination is an object. Until reading this I thought Lewis was in the second camp, but this sounds like object-nihilism, as in Van Inwagen and Merricks.
The one has different truths from the many; it is one rather than many, one rather than six [Lewis]
     Full Idea: What's true of the many is not exactly what's true of the one. After all they are many while it is one. The number of the many is six, whereas the number of the fusion is one.
     From: David Lewis (Parts of Classes [1991], 3.6)
     A reaction: Together with Idea 15521, this nicely illustrates the gulf between commitment to ontology and commitment to truths. The truths about a fusion change, while its ontology remains the same. Possibly this is the key to all of metaphysics.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
Lewis only uses fusions to create unities, but fusions notoriously flatten our distinctions [Oliver/Smiley on Lewis]
     Full Idea: Lewis employs mereological fusion as his sole method of making one thing out of many, and fusion is notorious for the way it flattens out and thereby obliterates distinctions.
     From: comment on David Lewis (Parts of Classes [1991]) by Oliver,A/Smiley,T - What are Sets and What are they For? 3.1
     A reaction: I take this to be a key point in the discussion of mereology in ontological contexts. As a defender of intrinsic structural essences, I have no use for mereological fusions, and look for a quite different identity for 'wholes'.
A commitment to cat-fusions is not a further commitment; it is them and they are it [Lewis]
     Full Idea: Given a prior commitment to cats, a commitment to cat-fusions is not a further commitment. The fusion is nothing over and above the cats that compose it. It just is them. They just are it.
     From: David Lewis (Parts of Classes [1991], p.81), quoted by Achille Varzi - Mereology 4.3
     A reaction: I take this to make Lewis a nominalist, saying the same thing that Goodman said about Utah in Idea 10657. Any commitment to cat-fusions being more than the cats, or Utah being more than its counties, strikes me as crazy.
Lewis prefers giving up singletons to giving up sums [Lewis, by Fine,K]
     Full Idea: In the face of the conflict between mereology and set theory, Lewis has advocated giving up the existence of singletons rather than sums.
     From: report of David Lewis (Parts of Classes [1991]) by Kit Fine - Replies on 'Limits of Abstraction' 1
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / a. Qualities in perception
Properties don't possess ways they are, because that just is the property [Heil]
     Full Idea: Objects possess properties, but I am sceptical of the idea that properties possess properties; just as a property is a way some object is, a property of a property would be a way a property is, but that is just the property itself.
     From: John Heil (From an Ontological Point of View [2003], 12.1)
     A reaction: This is quite a good defence of the idea that properties are qualities as well as dispositions. However, if we make the qualities of properties into secondary qualities, and the dispositions into primary qualities, the absurdity melts away.
Some say qualities are parts of things - as repeatable universals, or as particulars [Lewis]
     Full Idea: Some philosophers propose that things have their qualities by having them as parts, either as repeatable universals (Goodman), or as particulars (Donald Williams).
     From: David Lewis (Parts of Classes [1991], 2.1 n2)
     A reaction: He refers to 'qualities' rather than 'properties', presumably because this view makes them all intrinsic to the object. Is being 'handsome' a part of a person?
If properties were qualities without dispositions, they would be undetectable [Heil]
     Full Idea: A pure quality, a property altogether lacking in dispositionality, would be undetectable and would, in one obvious sense, make no difference to its possessor.
     From: John Heil (From an Ontological Point of View [2003], 11.4)
     A reaction: This seems to be a very forceful and simple reason why we cannot view properties simply as qualities of things. Heil wants properties to be dispositions and qualities; personally I would vote for them just being dispositions or powers.
Can we distinguish the way a property is from the property? [Heil]
     Full Idea: It is not clear to me that we easily distinguish ways a property is from the property itself.
     From: John Heil (From an Ontological Point of View [2003], 11.6)
     A reaction: To defend properties as qualities, he is confusing ontology and epistemology. Presumably he means by 'ways a property is' what I would prefer to call 'ways a property seems to be'. I don't believe a smell is simply what it seems to be.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / b. Primary/secondary
Objects only have secondary qualities because they have primary qualities [Heil]
     Full Idea: Secondary qualities are not distinct from primary qualities: an object's possession of a given secondary quality is a matter of its possession of certain complex primary qualities.
     From: John Heil (From an Ontological Point of View [2003], 17.3)
     A reaction: The bottom line here is that, if essentialism is right, colours are not properties at all (see Idea 5456). Heil wants to subsume secondary properties within primary properties. I think we should sharply distinguish them.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
Secondary qualities are just primary qualities considered in the light of their effect on us [Heil]
     Full Idea: Secondary qualities are just ordinary properties - roughly, Locke's primary qualities - considered in the light of their effects on us.
     From: John Heil (From an Ontological Point of View [2003], 14.10)
     A reaction: Unconvincing. If they only acquire their ontological status as primary qualities if they have to be considered in relation to something (us), then that is not a primary quality.
Colours aren't surface properties, because of radiant sources and the colour of the sky [Heil]
     Full Idea: Theories that take colours to be properties of the surfaces of objects have difficulty accounting for a host of phenomena including coloured light emitted by radiant sources and so-called film colours (the colour of the sky, for instance).
     From: John Heil (From an Ontological Point of View [2003], 17.4)
     A reaction: Personally I never thought that colours might be actual properties of surfaces, but it is nice to have spelled out a couple of instances that make it very implausible. Neon and sodium lights I take to be examples of the first case.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / e. Primary/secondary critique
Treating colour as light radiation has the implausible result that tomatoes are not red [Heil]
     Full Idea: Theories that tie colours to features of light radiation deal with radiant and diffused colours, but yield implausible results for objects; tomatoes are not red, on such a view, but merely reflect red light.
     From: John Heil (From an Ontological Point of View [2003], 17.4)
     A reaction: I see absolutely no problem with the philosophical denial that tomatoes are actually red, while continuing to use 'red' of tomatoes in the normal way. When we analyse our processes of knowledge acquisition, we must give up 'common sense'.
13. Knowledge Criteria / E. Relativism / 6. Relativism Critique
If the world is just texts or social constructs, what are texts and social constructs? [Heil]
     Full Idea: For those who regard the world as text or a social construct, are texts and social constructs real entities? If they are, what are they?
     From: John Heil (From an Ontological Point of View [2003], 20.6)
     A reaction: A nice turn-the-tables question. The oldest attacks of all on scepticism and relativism consist of showing that the positions themselves rest on knowledge or truth. Nietzsche may be the best model for relativists. E.g. Idea 4420.
14. Science / A. Basis of Science / 2. Demonstration
Demonstration provides depth of understanding and explanation (rather than foundations) [Kretzmann/Stump]
     Full Idea: According to Aquinas, what demonstration provides is not so much knowledge as conceived by foundationalists as depth of understanding and explanatory insight.
     From: Kretzmann/Stump (Aquinas, Thomas [2005]), quoted by Kretzmann/Stump - Aquinas, Thomas 11
     A reaction: It was noticeable that Aristotle didn't make clear what demonstration aims to achieve, and he didn't employ it elsewhere in his writings. We aim for understanding, not for well grounded propositions. Understanding needs implications and mechanisms.
14. Science / B. Scientific Theories / 1. Scientific Theory
If the world is theory-dependent, the theories themselves can't be theory-dependent [Heil]
     Full Idea: If the world is somehow theory-dependent, this implies, on pain of a regress, that theories are not theory-dependent.
     From: John Heil (From an Ontological Point of View [2003], 06.4)
     A reaction: I am not sure where this puts the ontology of theories, but this is a nice question, of a type which never seems to occur to your more simple-minded relativist.
14. Science / B. Scientific Theories / 2. Aim of Science
Science is sometimes said to classify powers, neglecting qualities [Heil]
     Full Idea: The sciences are sometimes said to be in the business of identifying and classifying powers; the mass of an electron, its spin and charge, could be regarded as powers possessed by the electron; science is silent on an electron's qualities.
     From: John Heil (From an Ontological Point of View [2003], 11.2)
     A reaction: Heil raises the possibility that qualities are real, despite the silence of science; he wants colour to be a real quality. I like the simpler version of science. Qualities are the mental effects of powers; there exist substances, powers and effects.
14. Science / D. Explanation / 2. Types of Explanation / j. Explanations by reduction
One form of explanation is by decomposition [Heil]
     Full Idea: One form of explanation is by decomposition.
     From: John Heil (From an Ontological Point of View [2003], 19.8)
     A reaction: This is a fancy word for taking it apart, presumably to see how it works, which implies a functional explanation, rather than to see what it is made of, which seeks an ontological explanation. Simply 'decomposing' something wouldn't in itself explain.
15. Nature of Minds / B. Features of Minds / 4. Intentionality / b. Intentionality theories
Dispositionality provides the grounding for intentionality [Heil]
     Full Idea: Dispositionality provides the grounding for intentionality.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: This is a view with which I am sympathetic, though I am not sure if it explains anything. It would be necessary to identify a disposition of basic matter that could be built up into the disposition of a brain to think about things.
Intentionality now has internalist (intrinsic to thinkers) and externalist (environment or community) views [Heil]
     Full Idea: Nowadays philosophers concerned with intentionality divide into two camps. Internalists epitomise a traditional approach to thought, as intrinsic features of thinkers; externalists say it depends on contextual factors (environment or community).
     From: John Heil (From an Ontological Point of View [2003], 18.2)
     A reaction: This is basic to understanding modern debates (those that grow out of Putnam's Twin Earth). Externalism is fashionable, but I am reluctant to shake off my quaint internalism. Start by separating strict and literal meaning from speaker's meaning.
15. Nature of Minds / B. Features of Minds / 5. Qualia / c. Explaining qualia
Qualia are not extra appendages, but intrinsic ingredients of material states and processes [Heil]
     Full Idea: Properties of conscious experience, the so-called qualia, are not dangling appendages to material states and processes but intrinsic ingredients of those states and processes.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: Personally I am inclined to the view that qualia are intrinsic to the processes and NOT to the 'states'. Heil must be right, though. I am sure qualia are not just epiphenomena - they are too useful.
17. Mind and Body / A. Mind-Body Dualism / 7. Zombies
Philosophers' zombies aim to show consciousness is over and above the physical world [Heil]
     Full Idea: Philosophers' zombies (invented by Robert Kirk) differ from the zombies of folklore; they are intended to make clear the idea that consciousness is an addition of being, something 'over and above' the physical world.
     From: John Heil (From an Ontological Point of View [2003], 20.1 n1)
     A reaction: The famous defender of zombies is David Chalmers. You can't believe in zombies if you believe (as I do) that 'the physical entails the mental'. Could there be redness without something that is red? If consciousness is extra, what is conscious?
Zombies are based on the idea that consciousness relates contingently to the physical [Heil]
     Full Idea: The possibility of zombies is founded on the idea that consciousness is related contingently to physical states and processes.
     From: John Heil (From an Ontological Point of View [2003], 20.3)
     A reaction: The question is, how do you decide whether the relationship is contingent or necessary? Hence the interest in whether conceivability entails possibility. Kripke attacks the idea of contingent identity, pointing towards necessity, and away from zombies.
Functionalists deny zombies, since identity of functional state means identity of mental state [Heil]
     Full Idea: Functionalists deny that zombies are possible since states of mind (including conscious states) are purely functional states. If two agents are in the same functional state, regardless of qualitative difference, they are in the same mental state.
     From: John Heil (From an Ontological Point of View [2003], 20.5)
     A reaction: In its 'brief' form this idea begins to smell of tautology. Only the right sort of functional state would entail a mental state, and how else can that functional state be defined, apart from its leading to a mental state?
17. Mind and Body / C. Functionalism / 1. Functionalism
Functionalists say objects can be the same in disposition but differ in quality [Heil]
     Full Idea: A central tenet of functionalism is that objects can be dispositionally indiscernible but differ qualitatively as much as you please.
     From: John Heil (From an Ontological Point of View [2003], 11.3)
     A reaction: This refers to the multiple realisability of functions. Presumably we reconcile essentialism with the functionalist view by saying that dispositions result from combinations of qualities. A unique combination of qualities will necessitate a disposition.
17. Mind and Body / C. Functionalism / 8. Functionalism critique
Functionalism cannot explain consciousness just by functional organisation [Heil]
     Full Idea: Functionalism has been widely criticized on the grounds that it is implausible to think that functional organization alone could suffice for conscious experience.
     From: John Heil (From an Ontological Point of View [2003], 20.2)
     A reaction: He cites Block's 'Chinese Mind' as an example. The obvious reply is that you can't explain consciousness with a lump of meat, or with behaviour, or with an anomalous property, or even with a non-physical substance.
17. Mind and Body / D. Property Dualism / 6. Mysterianism
The 'explanatory gap' is used to say consciousness is inexplicable, at least with current concepts [Heil]
     Full Idea: The expression 'explanatory gap' was coined by Joseph Levine in 1983. McGinn and Chalmers have invoked it in defence of the view that consciousness is physically inexplicable, and Nagel that it is inexplicable given existing conceptual resources.
     From: John Heil (From an Ontological Point of View [2003], 19.8 n14)
     A reaction: Coining a few concepts isn't going to help, but discovering more about the brain might. With computer simulations we will 'see' more of the physical end of thought. Psychologists may break thought down into physically more manageable components.
17. Mind and Body / E. Mind as Physical / 5. Causal Argument
If a car is a higher-level entity, distinct from its parts, how could it ever do anything? [Heil]
     Full Idea: If we regard a Volvo car as a higher-level entity with its own independent reality, something distinct from its constituents (arranged in particular ways and variously connected to other things), we render mysterious how Volvos could do anything at all.
     From: John Heil (From an Ontological Point of View [2003], 02.3)
     A reaction: This seems to me perhaps the key reason why we have to be reductionists. The so-called 'bridge laws' from mind to brain are not just needed to explain the mind, they are also essential to show how a mind would cause behaviour.
17. Mind and Body / E. Mind as Physical / 7. Anti-Physicalism / b. Multiple realisability
Multiple realisability is actually one predicate applying to a diverse range of properties [Heil]
     Full Idea: Cases of multiple realisability are typically cases in which some predicate ('is red', 'is in pain') applies to an object in virtue of that object's possession of any of a diverse range of properties.
     From: John Heil (From an Ontological Point of View [2003], 14.8)
     A reaction: If the properties are diverse, why does one predicate apply to them? I take it that in the case of the pain, the predicate is ambiguous in applying to the behaviour or the phenomenal property. Same behaviour is possible with many qualia.
18. Thought / C. Content / 6. Broad Content
Externalism is causal-historical, or social, or biological [Heil]
     Full Idea: Some externalists focus on causal-historical connections, others emphasise social matters (especially thinkers' linguistic communities), still others focus on biological function.
     From: John Heil (From an Ontological Point of View [2003], 18.5 n6)
     A reaction: Helpful. The social view strikes me as the one to take most seriously (allowing for contextual views of justification, and for the social role of experts). The problem is to combine the social view with realism and a robust view of truth.
18. Thought / C. Content / 7. Narrow Content
Intentionality is based in dispositions, which are intrinsic to agents, suggesting internalism [Heil]
     Full Idea: I suggest that intentionality is grounded in the dispositionalities of agents. Dispositions are intrinsic to agents, so this places me on the side of the internalists and against the externalists.
     From: John Heil (From an Ontological Point of View [2003], 18.4)
     A reaction: I think this is a key idea, and the right view. The key question is whether we see intentionality as active or passive. The externalist view seems to see the brain as a passive organ which the world manipulates. If the brain is active, what is it doing?
19. Language / A. Nature of Meaning / 2. Meaning as Mental
The Picture Theory claims we can read reality from our ways of speaking about it [Heil]
     Full Idea: The theory of language which I designate the 'Picture Theory' says that language pictures reality in roughly the sense that we can 'read off' features of reality from our ways of speaking about it.
     From: John Heil (From an Ontological Point of View [2003], 03.2)
     A reaction: Heil, quite rightly, attacks this view very strongly. I think of it as the great twentieth century philosophical heresy, that leads to shocking views like relativism and anti-realism.
19. Language / D. Propositions / 2. Abstract Propositions / b. Propositions as possible worlds
If propositions are states of affairs or sets of possible worlds, these lack truth values [Heil]
     Full Idea: When pressed, philosophers will describe propositions as states of affairs or sets of possible worlds. But wait! Neither sets of possible worlds nor states of affairs - electrons being negatively charged, for instance - have truth values.
     From: John Heil (From an Ontological Point of View [2003], Intro)
     A reaction: I'm not sure that I see a problem. A pure proposition, expressed as, say "there is a giraffe on the roof" only acquires a truth value at the point where you assert it or believe it. There IS a possible world where there is a giraffe on the roof.
26. Natural Theory / C. Causation / 9. General Causation / b. Nomological causation
The standard view is that causal sequences are backed by laws, and between particular events [Heil]
     Full Idea: The notion that every causal sequence if backed by a law, like the idea that causation is a relation among particular events, forms a part of philosophy's Humean heritage.
     From: John Heil (From an Ontological Point of View [2003], 04.3)
     A reaction: This nicely pinpoints a view that needs to come under attack. I take the view that there are no 'laws' - other than the regularities in behaviour that result from the interaction of essential dispositional properties. Essences don't need laws.
27. Natural Reality / F. Chemistry / 2. Modern Elements
The real natural properties are sparse, but there are many complex properties [Heil]
     Full Idea: I am sympathetic to the idea that the real properties are 'sparse'; ...but if, in counting kinds of property, we include complex properties as well as simple properties, the image of sparseness evaporates.
     From: John Heil (From an Ontological Point of View [2003], 13.4)
     A reaction: This seems right to me, and invites the obvious question of which are the sparse real properties. Presumably we let the physicists tell us that, though Heil wants to include qualities like phenomenal colour, which physicists ignore.