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All the ideas for 'fragments/reports', 'A Structural Account of Mathematics' and 'Objects and Persons'

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47 ideas

1. Philosophy / G. Scientific Philosophy / 3. Scientism
Empirical investigation can't discover if holes exist, or if two things share a colour [Merricks]
     Full Idea: Ontology is not empirical, but ontologists do make discoveries; empirical investigation won't discover that holes exist; we see that two things are the same colour, but a philosopher must resolve whether one universal is present in both.
     From: Trenton Merricks (Objects and Persons [2003], Pref)
     A reaction: This is one of the best, simplest and clearest statements I have encountered of the autonomy of philosophy. One may, of course, respond by saying 'who cares?', but then who cares about quarks, or the economy of the Spanish Empire?
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
Realists about sets say there exists a null set in the real world, with no members [Chihara]
     Full Idea: In the Gödelian realistic view of set theory the statement that there is a null set as the assertion of the existence in the real world of a set that has no members.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 11.6)
     A reaction: It seems to me obvious that such a claim is nonsense on stilts. 'In the beginning there was the null set'?
We only know relational facts about the empty set, but nothing intrinsic [Chihara]
     Full Idea: Everything we know about the empty set is relational; we know that nothing is the membership relation to it. But what do we know about its 'intrinsic properties'?
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.5)
     A reaction: Set theory seems to depend on the concept of the empty set. Modern theorists seem over-influenced by the Quine-Putnam view, that if science needs it, we must commit ourselves to its existence.
In simple type theory there is a hierarchy of null sets [Chihara]
     Full Idea: In simple type theory, there is a null set of type 1, a null set of type 2, a null set of type 3..... (Quine has expressed his distaste for this).
     From: Charles Chihara (A Structural Account of Mathematics [2004], 07.4)
     A reaction: It is bad enough trying to individuate the unique null set, without whole gangs of them drifting indistinguishably through the logical fog. All rational beings should share Quine's distaste, even if Quine is wrong.
The null set is a structural position which has no other position in membership relation [Chihara]
     Full Idea: In the structuralist view of sets, in structures of a certain sort the null set is taken to be a position (or point) that will be such that no other position (or point) will be in the membership relation to it.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 11.6)
     A reaction: It would be hard to conceive of something having a place in a structure if nothing had a relation to it, so is the null set related to singeton sets but not there members. It will be hard to avoid Platonism here. Set theory needs the null set.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
What is special about Bill Clinton's unit set, in comparison with all the others? [Chihara]
     Full Idea: What is it about the intrinsic properties of just that one unit set in virtue of which Bill Clinton is related to just it and not to any other unit sets in the set-theoretical universe?
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.5)
     A reaction: If we all kept pet woodlice, we had better not hold a wood louse rally, or we might go home with the wrong one. My singleton seems seems remarkably like yours. Could we, perhaps, swap, just for a change?
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
The set theorist cannot tell us what 'membership' is [Chihara]
     Full Idea: The set theorist cannot tell us anything about the true relationship of membership.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.5)
     A reaction: If three unrelated objects suddenly became members of a set, it is hard to see how the world would have changed, except in the minds of those thinking about it.
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
ZFU refers to the physical world, when it talks of 'urelements' [Chihara]
     Full Idea: ZFU set theory talks about physical objects (the urelements), and hence is in some way about the physical world.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 11.5)
     A reaction: This sounds a bit surprising, given that the whole theory would appear to be quite unaffected if God announced that idealism is true and there are no physical objects.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
A pack of wolves doesn't cease when one member dies [Chihara]
     Full Idea: A pack of wolves is not thought to go out of existence just because some member of the pack is killed.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 07.5)
     A reaction: The point is that the formal extensional notion of a set doesn't correspond to our common sense notion of a group or class. Even a highly scientific theory about wolves needs a loose notion of a wolf pack.
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
The mathematics of relations is entirely covered by ordered pairs [Chihara]
     Full Idea: Everything one needs to do with relations in mathematics can be done by taking a relation to be a set of ordered pairs. (Ordered triples etc. can be defined as order pairs, so that <x,y,z> is <x,<y,z>>).
     From: Charles Chihara (A Structural Account of Mathematics [2004], 07.2)
     A reaction: How do we distinguish 'I own my cat' from 'I love my cat'? Or 'I quite like my cat' from 'I adore my cat'? Nevertheless, this is an interesting starting point for a discussion of relations.
5. Theory of Logic / K. Features of Logics / 2. Consistency
Sentences are consistent if they can all be true; for Frege it is that no contradiction can be deduced [Chihara]
     Full Idea: In first-order logic a set of sentences is 'consistent' iff there is an interpretation (or structure) in which the set of sentences is true. ..For Frege, though, a set of sentences is consistent if it is not possible to deduce a contradiction from it.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 02.1)
     A reaction: The first approach seems positive, the second negative. Frege seems to have a higher standard, which is appealing, but the first one seems intuitively right. There is a possible world where this could work.
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Analytic geometry gave space a mathematical structure, which could then have axioms [Chihara]
     Full Idea: With the invention of analytic geometry (by Fermat and then Descartes) physical space could be represented as having a mathematical structure, which could eventually lead to its axiomatization (by Hilbert).
     From: Charles Chihara (A Structural Account of Mathematics [2004], 02.3)
     A reaction: The idea that space might have axioms seems to be pythagoreanism run riot. I wonder if there is some flaw at the heart of Einstein's General Theory because of this?
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / c. Nominalist structuralism
We can replace existence of sets with possibility of constructing token sentences [Chihara, by MacBride]
     Full Idea: Chihara's 'constructability theory' is nominalist - mathematics is reducible to a simple theory of types. Instead of talk of sets {x:x is F}, we talk of open sentences Fx defining them. Existence claims become constructability of sentence tokens.
     From: report of Charles Chihara (A Structural Account of Mathematics [2004]) by Fraser MacBride - Review of Chihara's 'Structural Acc of Maths' p.81
     A reaction: This seems to be approaching the problem in a Fregean way, by giving an account of the semantics. Chihara is trying to evade the Quinean idea that assertion is ontological commitment. But has Chihara retreated too far? How does he assert existence?
7. Existence / B. Change in Existence / 4. Events / a. Nature of events
Prolonged events don't seem to endure or exist at any particular time [Merricks]
     Full Idea: That events endure is difficult to reconcile with the claim that, say, the American Civil War existed; for such an event seems never to have been 'wholly present' at any single time.
     From: Trenton Merricks (Objects and Persons [2003], §3 n14)
     A reaction: A nice problem example for those who, like Kim, want their ontology to include events. Personally I am happy to allow some vagueness here. The Civil War only became an 'event' on the day it finished. An event's time need not be an instant.
7. Existence / D. Theories of Reality / 10. Vagueness / b. Vagueness of reality
A crumbling statue can't become vague, because vagueness is incoherent [Merricks]
     Full Idea: Some would say that annihilating grains of stone from the statue of David (playing the 'Sorites Game') could never make its identity vague, because metaphysical vagueness is simply unintelligible.
     From: Trenton Merricks (Objects and Persons [2003], §2.II)
     A reaction: He cites Russell, Dummett and Lewis in support. But Russell is a logical atomist, and Lewis says identity is composition. It strikes me as obvious that identity can be vague; the alternative is the absurdities of the Sorites paradox.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / e. Ontological commitment problems
If a successful theory confirms mathematics, presumably a failed theory disconfirms it? [Chihara]
     Full Idea: If mathematics shares whatever confirmation accrues to the theories using it, would it not be reasonable to suppose that mathematics shares whatever disconfirmation accrues to the theories using it?
     From: Charles Chihara (A Structural Account of Mathematics [2004], 05.8)
     A reaction: Presumably Quine would bite the bullet here, although maths is much closer to the centre of his web of belief, and so far less likely to require adjustment. In practice, though, mathematics is not challenged whenever an experiment fails.
No scientific explanation would collapse if mathematical objects were shown not to exist [Chihara]
     Full Idea: Evidently, no scientific explanations of specific phenomena would collapse as a result of any hypothetical discovery that no mathematical objects exist.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 09.1)
     A reaction: It is inconceivable that anyone would challenge this claim. A good model seems to be drama; a play needs commitment from actors and audience, even when we know it is fiction. The point is that mathematics doesn't collapse either.
8. Modes of Existence / B. Properties / 4. Intrinsic Properties
Intrinsic properties are those an object still has even if only that object exists [Merricks]
     Full Idea: Intrinsic properties are, by and large, those properties that an object can exemplify even if that object and its parts (if any) are the only objects that exist.
     From: Trenton Merricks (Objects and Persons [2003], §4.I)
     A reaction: This leads to all sorts of properties that seemed intrinsic turning out to be relational. In what sense would a single object have mass, or impenetrability?
9. Objects / A. Existence of Objects / 1. Physical Objects
I say that most of the objects of folk ontology do not exist [Merricks]
     Full Idea: I argue against the existence of most of the objects alleged to exist by what we might call 'folk ontology'.
     From: Trenton Merricks (Objects and Persons [2003], §1)
     A reaction: This is the programme for Merricks's heroic book, denying (quite plausibly) the need for large objects in our ontology. It seems that ontology must multiply its entities prodigiously, or else be austere in the extreme. Is there no middle way?
Is swimming pool water an object, composed of its mass or parts? [Merricks]
     Full Idea: Some - such as those who endorse unrestricted composition or those who believe in a kind of entity called 'a mass' - say that 'the water in the swimming pool' refers to a big material object.
     From: Trenton Merricks (Objects and Persons [2003], §2.I)
     A reaction: A well-chosen example to support his thesis that large objects don't (strictly) exist. We certainly must not say (in Quine fashion) that we must accept the ontology of our phrases. I cut nature at the joints, and I say a pool is an obvious joint.
9. Objects / A. Existence of Objects / 5. Simples
We can eliminate objects without a commitment to simples [Merricks]
     Full Idea: Eliminativism about physical objects does not require a commitment to (or against) simples.
     From: Trenton Merricks (Objects and Persons [2003], §1.I)
     A reaction: His strategy is to eliminate objects in favour of whatever it is (an unknown) to which objects actually reduce. His point seems to be clearly correct, just as I might eliminate 'life' from my ontology, without quite knowing what it is.
9. Objects / A. Existence of Objects / 6. Nihilism about Objects
Merricks agrees that there are no composite objects, but offers a different semantics [Merricks, by Liggins]
     Full Idea: Merricks agrees with van Inwagen that there are no composite objects, but disagrees with him about the semantics of talk about material objects.
     From: report of Trenton Merricks (Objects and Persons [2003]) by David Liggins - Nihilism without Self-Contradiction 4
     A reaction: Van Inwagen has one semantics for folk talk, and another semantics 'for the philosophy room'. Merricks seems to have an error theory of folk semantics (i.e. the folk don't understand what they are saying).
The 'folk' way of carving up the world is not intrinsically better than quite arbitrary ways [Merricks]
     Full Idea: It is hard to see why the folk way of carving up the material world should - barring further argument - be elevated to a loftier status than the unrestricted compositionist way.
     From: Trenton Merricks (Objects and Persons [2003], §3.III)
     A reaction: There are some right ways to carve up the world, though there is also the capacity to be quite arbitrary, if it is useful, or even amusing. Thus Cyprus is an island (fact), Britons are a nation (useful), and Arsenal fans are sad (amusing).
If atoms 'arranged baseballwise' break a window, that analytically entails that a baseball did it [Merricks, by Thomasson]
     Full Idea: Given the proper understanding of 'arranged baseballwise', the fact that atoms arranged baseballwise are causally relevant to a shattering analytically entails that a baseball is.
     From: report of Trenton Merricks (Objects and Persons [2003], 3) by Amie L. Thomasson - Ordinary Objects 01.3
     A reaction: This is the key argument of Thomasson's book. Presumably, following Idea 14471, 'I bought some atoms arranged baseballwise' is held to entail 'I bought a baseball'. That seems to beg the question against Van Inwagen and Merricks.
Overdetermination: the atoms do all the causing, so the baseball causes no breakage [Merricks]
     Full Idea: The Overdetermination Argument: a baseball is irrelevant to whether its atoms shatter a window, the shattering is caused by the atoms in concert, the shattering is not overdetermined, so if the baseball exists it doesn't cause the shattering.
     From: Trenton Merricks (Objects and Persons [2003], 3)
     A reaction: An obvious thought is that no individual atom does any sort of breaking at all - it is only when they act as a team, and an appropriate name for the team is a 'baseball', and the team is real.
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
Clay does not 'constitute' a statue, as they have different persistence conditions (flaking, squashing) [Merricks]
     Full Idea: A statue is not identical with its constituent lump of clay because they have different persistence conditions; the statue, but not the lump, could survive the loss of a few smallish bits, and the lump, but not the statue, could survive being squashed.
     From: Trenton Merricks (Objects and Persons [2003], §2.III)
     A reaction: I don't see why a lump can't survive losing a few bits (if the lump never had a precise identity), but it is hard to argue that squashing is a problem. However, presumably the identity (or constitution) between lump and statue is not a necessity.
9. Objects / C. Structure of Objects / 5. Composition of an Object
'Unrestricted composition' says any two things can make up a third thing [Merricks]
     Full Idea: If my dog and the top half of my tree compose an object, this is defended under the title of 'unrestricted (universal) composition', the thesis that any two things compose something.
     From: Trenton Merricks (Objects and Persons [2003], §1.II)
     A reaction: David Lewis is cited amongst those defending this thesis. My intuition is against this thesis, because I think identity is partly dictated by nature, and is not entirely conventional. You can force an identity, but you feel the 'restriction'.
Composition as identity is false, as identity is never between a single thing and many things [Merricks]
     Full Idea: One of the most obvious facts about identity is that it holds one-one (John and Mr Smith) and perhaps many-many (John+Mary and Mr Smith+Miss Jones), but never one-many. It follows that composition as identity (things are their parts) is false.
     From: Trenton Merricks (Objects and Persons [2003], §1.IV)
     A reaction: This assumes that 'having identity' and 'being identical to' are the same concept. I agree with his conclusion, but am not convinced by the argument. I'm not even quite clear why John and May can't be identical to the Smiths.
Composition as identity is false, as it implies that things never change their parts [Merricks]
     Full Idea: Composition as identity implies that no persisting object ever changes its parts, which is clearly false, so composition as identity is false.
     From: Trenton Merricks (Objects and Persons [2003], §1.IV)
     A reaction: Presumably Lewis can say that when a thing subtly changes its parts, it really does lose its strict identity, but becomes another 'time-slice' or close 'counterpart' of the original object. This is a coherent view, but I disagree. I'm a believer.
There is no visible difference between statues, and atoms arranged statuewise [Merricks]
     Full Idea: If we imagine a world like ours except that, while there are atoms arranged statuewise in that world, there are no statues, ...no amount of looking around could distinguish that imagined world from ours.
     From: Trenton Merricks (Objects and Persons [2003], §2.V)
     A reaction: This is one of his arguments for ontological eliminativism about physical objects. If we accept the argument, it will wreak havoc with our entire ontology, and we will end up anti-realists. I say you have to see statues - you just can't miss them.
9. Objects / C. Structure of Objects / 6. Constitution of an Object
'Composition' says things are their parts; 'constitution' says a whole substance is an object [Merricks]
     Full Idea: Composition as identity claims that a single object is identical with the many parts it comprises; constitution as identity says that a single object (a statue) is identical with a single object (clay) that 'constitutes' it.
     From: Trenton Merricks (Objects and Persons [2003], §1 n11)
     A reaction: The constitution view has been utilised (by Lynn Rudder Baker) to give an account of personal identity as constituted by a human body. Neither sounds quite right to me; the former view misses something about reality; the latter doesn't explain much.
It seems wrong that constitution entails that two objects are wholly co-located [Merricks]
     Full Idea: Many philosophers deny that two numerically distinct physical objects could be 'wholly co-located'.
     From: Trenton Merricks (Objects and Persons [2003], §2.III)
     A reaction: A fish can be located in a river; the Appenines can be located in Italy. If you accept the objection you will probably have to accept identity-as-composition, or object-eliminativism. One object can have two causal roles, supporting two identities.
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
Objects decompose (it seems) into non-overlapping parts that fill its whole region [Merricks]
     Full Idea: Intuitively, an object's parts at one level of decomposition are parts of that object that do not overlap and that, collectively, fill the whole region the object fills.
     From: Trenton Merricks (Objects and Persons [2003], §1.II)
     A reaction: A nice case where 'intuition' must be cited as the basis for the claim, and yet it is hard to see how anyone could possibly disagree. Exhibit 73 in favour of rationalism. This ideas shows the structure of nature and the workings of our minds.
9. Objects / E. Objects over Time / 13. No Identity over Time
Eliminativism about objects gives the best understanding of the Sorites paradox [Merricks]
     Full Idea: I say we should endorse eliminativism about physical objects, because it offers the most plausible understanding of what occurs during the Sorites Game (eliminating grains of a thing one at a time).
     From: Trenton Merricks (Objects and Persons [2003], §2.II)
     A reaction: That is one route to go in explaining the paradox (i.e. by saying there never was a 'heap' in the first place). I suspect a better route is to say that heaps really exist as natural phenomena, but they suffer from vague identity and borderline cases.
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
If my counterpart is happy, that is irrelevant to whether I 'could' have been happy [Merricks]
     Full Idea: The existence of someone in another world who is a lot like me, but happier, is irrelevant to whether I - this very person - could have been happier, even if we call that other-worldly someone 'my counterpart'.
     From: Trenton Merricks (Objects and Persons [2003], §1.IV)
     A reaction: He says this is a familiar objection. I retain a lingering deterministic doubt about whether it ever makes to sense to say that I 'could' have been happy, given that I am not. It does seem to make sense to say that I was close to happiness, but missed it.
13. Knowledge Criteria / A. Justification Problems / 1. Justification / a. Justification issues
The 'warrant' for a belief is what turns a true belief into knowledge [Merricks]
     Full Idea: The 'warrant' for a belief is that, whatever it is, that makes the difference between mere true belief and knowledge.
     From: Trenton Merricks (Objects and Persons [2003], §7.II)
     A reaction: Hence a false belief could be well justified, but it could never be warranted. This makes warrant something like the externalist view of justification, a good supporting situation for a belief, rather than an inner awareness of support for it.
16. Persons / B. Nature of the Self / 7. Self and Body / a. Self needs body
You hold a child in your arms, so it is not mental substance, or mental state, or software [Merricks]
     Full Idea: When you hold your child, you do exactly that - hold the child himself or herself - and not some stand-in. This implies that we are not two substances, and we are not mental states nor akin to software.
     From: Trenton Merricks (Objects and Persons [2003], §4)
     A reaction: And it is not just a brain, either. This is a nice simple example to support the sensible view that a person is a type of animal. Like all other physical objects that is a bit vague, so we should not be distracted by borderline cases like brain bisection.
16. Persons / D. Continuity of the Self / 3. Reference of 'I'
Maybe the word 'I' can only refer to persons [Merricks]
     Full Idea: One might say that the word 'I' can only have a person as its reference.
     From: Trenton Merricks (Objects and Persons [2003], §2.IV)
     A reaction: To infer the existence of persons from this would be to commit what I think of as the Linguistic Fallacy, of deducing ontology directly from language. We might allow (Dennett fashion) that folk categories require the fiction of persons.
16. Persons / F. Free Will / 7. Compatibilism
Free will and determinism are incompatible, since determinism destroys human choice [Merricks]
     Full Idea: The main recent support for incompatibilism is the 'no choice' argument: we have no choice that the past and the laws of nature entail human actions, we have no choice about what the past or the laws are like, so we have no choice about our actions.
     From: Trenton Merricks (Objects and Persons [2003], §6.III)
     A reaction: Since I consider free will to be an absurd chimera, I think this argument involves a total misunderstanding of what a 'choice' is. Since the human brain is a wonderfully sophisticated choosing machine, our whole life consists of choices.
17. Mind and Body / D. Property Dualism / 4. Emergentism
Human organisms can exercise downward causation [Merricks]
     Full Idea: Human organisms have non-redundant causal powers, and so can exercise downward causation.
     From: Trenton Merricks (Objects and Persons [2003], §4.VII)
     A reaction: The hallmark of property dualism. This notion needs a lot more expansion and exploration than Merricks gives it, and I don't think it will be enough to provide 'free will', or even, as Merricks hopes, to place humans in a distinct ontological category.
18. Thought / C. Content / 7. Narrow Content
Before Creation it is assumed that God still had many many mental properties [Merricks]
     Full Idea: The belief of theists that God might never have created implies that there is a possible world that contains just a single entity with many conscious mental properties.
     From: Trenton Merricks (Objects and Persons [2003], §4.II)
     A reaction: So if we believe content is wide, we must believe that God was incapable of thought before creation, and thus couldn't plan creation, and so didn't create, and so the Creator is a logical impossibility. Cool.
The hypothesis of solipsism doesn't seem to be made incoherent by the nature of mental properties [Merricks]
     Full Idea: The hypothesis of solipsism, that I - an entity with many conscious mental properties - am all that exists, while surely false, is not rendered incoherent simply by the nature of the mental properties.
     From: Trenton Merricks (Objects and Persons [2003], §4.II)
     A reaction: This, along with the thought of a pre-Creation God, is a nice intuitive case for showing that we strongly believe in some degree of narrow content.
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
I prefer the open sentences of a Constructibility Theory, to Platonist ideas of 'equivalence classes' [Chihara]
     Full Idea: What I refer to as an 'equivalence class' (of line segments of a particular length) is an open sentence in my Constructibility Theory. I just use this terminology of the Platonist for didactic purposes.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 09.10)
     A reaction: This is because 'equivalence classes' is committed to the existence of classes, which is Quinean Platonism. I am with Chihara in wanting a story that avoids such things. Kit Fine is investigating similar notions of rules of construction.
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
Mathematical entities are causally inert, so the causal theory of reference won't work for them [Chihara]
     Full Idea: Causal theories of reference seem doomed to failure for the case of reference to mathematical entities, since such entities are evidently causally inert.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.3)
     A reaction: Presumably you could baptise a fictional entity such as 'Polonius', and initiate a social causal chain, with a tradition of reference. You could baptise a baby in absentia.
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
     Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes.
     From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078
     A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book.
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
'Gunk' is an individual possessing no parts that are atoms [Chihara]
     Full Idea: An 'atomless gunk' is defined to be an individual possessing no parts that are atoms.
     From: Charles Chihara (A Structural Account of Mathematics [2004], App A)
     A reaction: [Lewis coined it] If you ask what are a-toms made of and what are ideas made of, the only answer we can offer is that the a-toms are made of gunk, and the ideas aren't made of anything, which is still bad news for the existence of ideas.
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]
     Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness.
     From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42
     A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them.