structure for 'Objects'    |     alphabetical list of themes    |     unexpand these ideas

9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects

[what is involved in being part of something else]

27 ideas
Plato says only a one has parts, and a many does not [Plato, by Harte,V]
     Full Idea: In 'Parmenides' it is argued that a part cannot be part of a many, but must be part of something one.
     From: report of Plato (Parmenides [c.364 BCE], 157c) by Verity Harte - Plato on Parts and Wholes 3.2
     A reaction: This looks like the right way to go with the term 'part'. We presuppose a unity before we even talk of its parts, so we can't get into contradictions and paradoxes about their relationships.
Anything which has parts must be one thing, and parts are of a one, not of a many [Plato]
     Full Idea: The whole of which the parts are parts must be one thing composed of many; for each of the parts must be part, not of a many, but of a whole.
     From: Plato (Parmenides [c.364 BCE], 157c)
     A reaction: This is a key move of metaphysics, and we should hang on to it. The other way madness lies.
If a word has no parts and has a single identity, it turns out to be the same kind of thing as a letter [Plato]
     Full Idea: If a complex or a syllable has no parts and is a single identity, hasn't it turned out to be the same kind of thing as an element or letter?
     From: Plato (Theaetetus [c.368 BCE], 205d)
The contents of an explanatory formula are parts of the whole [Aristotle]
     Full Idea: The contents of the formula which explains a thing are parts of the whole.
     From: Aristotle (Metaphysics [c.324 BCE], 1023a24)
     A reaction: This is part of a catalogue of ways in which things can be parts [1023b08-25]. I like this, because it fits my general thesis, that the desire for explanation is the driving force behind our metaphysics.
Indivisibles are not parts, but the extrema of parts [Leibniz]
     Full Idea: Indivisibles are not parts, but the extrema of parts.
     From: Gottfried Leibniz (Pacidius Philalethi dialogue [1676], A6.3.565-6), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 1
     A reaction: This is incipient monadology, that the bottom level of division ceases to be parts of a thing, and arrives at a different order of entity, to explain the parts of things. Leibniz denies that this subdivision comes down to points.
Whatever is made up of parts is made up of parts of those parts [Mill]
     Full Idea: Whatever is made up of parts is made up of parts of those parts.
     From: John Stuart Mill (System of Logic [1843], 3.24.5)
     A reaction: Mill considers this principle to be fundamental to the possibilities of arithmetic. Presumably he thought of it as an inductive inference from our dealings with physical objects.
Class membership is not transitive, unlike being part of a part of the whole [Lesniewski, by George/Van Evra]
     Full Idea: Lesniewski distinguished the part-whole relationship from class membership. Membership is not transitive: if s is an element of t, and t of u, then s is not an element of u, whereas a part of a part is a part of the whole.
     From: report of Stanislaw Lesniewski (works [1916]) by George / Van Evra - The Rise of Modern Logic 7
     A reaction: If I am a member of a sports club, and my club is a member of the league, I am not thereby a member of the league (so clubs are classes, not wholes). This distinction is clearly fairly crucial in ontology.
In the military, persons are parts of parts of large units, but not parts of those large units [Rescher]
     Full Idea: In military usage, persons can be parts of small units, and small units parts of large ones; but persons are never parts of large units.
     From: Nicholas Rescher (Axioms for the Part Relation [1955]), quoted by Achille Varzi - Mereology 2.1
     A reaction: This much-cited objection to the transitivity of the 'part' relation seems very odd. There could hardly be an army or a regiment if there weren't soldiers to make up parts of it.
I think parthood involves causation, and not just a reasonably stable spatial relationship [Inwagen]
     Full Idea: I propose that parthood essentially involves causation. Too many philosophers have supposed that objects compose something when and only when they stand in some (more or less stable) spatial relationship to one another.
     From: Peter van Inwagen (Material Beings [1990], 09)
     A reaction: I have to say that I like this, even though it comes from a thinker who is close to nihilism about ordinary non-living objects. He goes on to say that only a 'life' provides the right sort of causal relationship.
We can deny whole objects but accept parts, by referring to them as plurals within things [Inwagen, by Liggins]
     Full Idea: Van Inwagen's claim that nothing has parts causes incredulity. ..But the problem is not with endorsing the sentence 'Some things have parts'; it is with interpreting this sentence by means of singular resources rather than plural ones.
     From: report of Peter van Inwagen (Material Beings [1990], 7) by David Liggins - Nihilism without Self-Contradiction
     A reaction: Van Inwagen notoriously denies the existence of normal physical objects. Liggins shows that modern formal plural quantification gives a better way of presenting his theory, by accepting tables and parts of tables as plurals of basic entities.
Parts seem to matter when it is just an object, but not matter when it is a kind of object [Jubien]
     Full Idea: When thought of just as an object, the parts of a thing seem definitive and their arrangement seems inconsequential. But when thought of as an object of a familiar kind it is reversed: the arrangement is important and the parts are inessential.
     From: Michael Jubien (Possibility [2009], 1.4)
     A reaction: This is analogous to the Ship of Theseus, where we say that the tour operator and the museum keeper give different accounts of whether it is the same ship. The 'kind' Jubien refers to is most likely to be a functional kind.
Parthood lacks the restriction of kind which most relations have [Yablo]
     Full Idea: Most relations obtain only between certain kinds of thing. To learn that x is a part of y, however, tells you nothing about x and y taken individually.
     From: Stephen Yablo (Aboutness [2014], 03.2)
     A reaction: Too sweeping. To be a part of crowd you have to be a person. To be part of the sea you have to be wet. It might depend on whether composition is unrestricted.
A 'temporary' part is a part at one time, but may not be at another, like a carburetor [Fine,K]
     Full Idea: First, a thing can be a part in a way that is relative to a time, for example, that a newly installed carburettor is now part of my car, whereas earlier it was not. (This will be called a 'temporary' part).
     From: Kit Fine (Things and Their Parts [1999], Intro)
     A reaction: [Cf Idea 13327 for the 'second' concept of part] I'm immediately uneasy. Being a part seems to be a univocal concept. He seems to be distinguishing parts which are necessary for identity from those which aren't. Fine likes to define by example.
A 'timeless' part just is a part, not a part at some time; some atoms are timeless parts of a water molecule [Fine,K]
     Full Idea: Second, an object can be a part of another in a way that is not relative to time ('timeless'). It is not appropriate to ask when it is a part. Thus pants and jacket are parts of the suit, atoms of a water molecule, and two pints part of a quart of milk.
     From: Kit Fine (Things and Their Parts [1999], Intro)
     A reaction: [cf Idea 13326 for the other concept of 'part'] Again I am uneasy that 'part' could have two meanings. A Life Member is a member in the same way that a normal paid up member is a member.
Spatial parts are just regions, but objects depend on and are made up of substantial parts [Heil]
     Full Idea: An object is not made up of its spatial parts: spatial parts are regions of some object. ...Complex objects, wholes, are made up of, and so depend on, their substantial parts.
     From: John Heil (The Universe as We Find It [2012], 03.1)
     A reaction: Presumably objects also 'depend on' their spatial parts, so I am not convinced that we have a sharp distinction here.
A 'gunky' universe would literally have no parts at all [Heil]
     Full Idea: Blancmange 'gunky' universes are not just universes with an endless number of parts. Rather a blancmange universe is a universe with no simple parts, no parts themselves lacking parts.
     From: John Heil (The Universe as We Find It [2012], 03.3)
     A reaction: Hm. Lewis seemed to think it was parts all the way down. Is gunk homogeneous stuff, or what is endlessly subdividable, or an infinite shrinking of parts? We demand clarity.
Parts may or may not be attached, demarcated, arbitrary, material, extended, spatial or temporal [Varzi]
     Full Idea: The word 'part' can used whether it is attached, or arbitrarily demarcated, or gerrymandered, or immaterial, or unextended, or spatial, or temporal.
     From: Achille Varzi (Mereology [2003], 1)
If 'part' is reflexive, then identity is a limit case of parthood [Varzi]
     Full Idea: Taking reflexivity as constitutive of the meaning of 'part' amounts to regarding identity as a limit case of parthood.
     From: Achille Varzi (Mereology [2003], 2.1)
     A reaction: A nice thought, but it is horribly 'philosophical', and a long way from ordinary usage and common sense (which is, I'm sorry to say, a BAD thing).
'Part' stands for a reflexive, antisymmetric and transitive relation [Varzi]
     Full Idea: It seems obvious that 'part' stands for a partial ordering, a reflexive ('everything is part of itself'), antisymmetic ('two things cannot be part of each other'), and transitive (a part of a part of a thing is part of that thing) relation.
     From: Achille Varzi (Mereology [2003], 2.1)
     A reaction: I'm never clear why the reflexive bit of the relation should be taken as 'obvious', since it seems to defy normal usage and common sense. It would be absurd to say 'I'll give you part of the cake' and hand you the whole of it. See Idea 10651.
The parthood relation will help to define at least seven basic predicates [Varzi]
     Full Idea: With a basic parthood relation, we can formally define various mereological predicates, such as overlap, underlap, proper part, over-crossing, under-crossing, proper overlap, and proper underlap.
     From: Achille Varzi (Mereology [2003], 2.2)
     A reaction: [Varzi offers some diagrams, but they need interpretation]
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.
We say 'b is part of a', 'b is a part of a', 'b are a part of a', or 'b are parts of a'. [Simons]
     Full Idea: There are four cases of possible forms of expression when a is made up of b: we say 'b is part of a', or 'b is a part of a', or 'b are a part of a', or 'b are parts of a'.
     From: Peter Simons (Parts [1987], 6.4)
     A reaction: Personally I don't want to make much of these observations of normal English usage, but they are still interesting, and Simons offers a nice discussion of them.
Parts must be of the same very general type as the wholes [Laycock]
     Full Idea: The notion of a part is such that parts must be of the same very general type - concrete, material or physical, for instance - as the wholes of which they are (said to be) parts.
     From: Henry Laycock (Words without Objects [2006], 2.9)
     A reaction: The phrase 'same very general type' cries out for investigation. Can an army contain someone who isn't much of a soldier? Can the Treasury contain a fear of inflation?
Nihilists needn't deny parts - they can just say that some of the xs are among the ys [Liggins]
     Full Idea: We can interpret '..is a part of..' as '..are among..': the xs are a part of the ys just when the xs are among the ys (though if the ys are 'one' then they would not have parts).
     From: David Liggins (Nihilism without Self-Contradiction [2008], 9)
     A reaction: The trouble is that this still leaves us with gerrymandered 'parts', in the form of xs that are scattered randomly among the ys. That's not what we mean by 'part'. No account of identity works if it leaves out coherent structure.
For three-dimensionalist parthood must be a three-place relation, including times [Koslicki]
     Full Idea: Parthood (for the three-dimensionalist) must be a three-place relation between pairs of objects and times, not the timeless two-place relation at work in the original Calculus of Individuals.
     From: Kathrin Koslicki (The Structure of Objects [2008], 2.2)
The parts may be the same type as the whole, like a building made of buildings [Koslicki]
     Full Idea: A building may be composed of proper parts which are themselves buildings; a particular pattern may be composed of proper parts which are themselves patterns (even the same pattern, on a smaller scale).
     From: Kathrin Koslicki (The Structure of Objects [2008], 7.2.12)
     A reaction: This strikes me as a rather important observation, if you are (erroneously) trying to establish the identity of a thing simply by categorising its type.
The weight of a wall is not the weight of its parts, since that would involve double-counting [Wasserman]
     Full Idea: We do not calculate the weight of something by summing the weights of all its parts - weigh bricks and the molecules of a wall and you will get the wrong result, since you have weighed some parts more than once.
     From: Ryan Wasserman (Material Constitution [2009], 2)
     A reaction: In fact the complete inventory of the parts of a thing is irrelevant to almost anything we would like to know about the thing. The parts must be counted at some 'level' of division into parts. An element can belong to many different sets.