Category: Wholes and Parts

Bonum Progressionis and the Value of One’s Life

The value of a whole is not determined merely by the values of the parts of the whole; the order of the parts also plays a role in determining the value of the whole.  One of several order principles governing the value of a whole is the bonum progressionis.  Glossing Franz Brentano, R. M. Chisholm (Brentano and Intrinsic Value, Cambridge, 1986, p. 71) writes:

The principle of the 'bonum progressionis' or the 'malum regressus' might be put by saying: 'If A is a situation in which a certain amount of value x is increased to a larger amount y, and if B is like A except that in B there is a decrease from the larger amount of value y to the smaller amount x, then A is preferable to B.'  Thus Brentano writes: "Let us think of a process which goes from good to bad or from a great good to a lesser good;then compare it to one which goes in the opposite direction.  The latter shows itself as the one to be preferred.  This holds even if the sum of the goods in the one process is equal to that in the other.  And our preference in this case is one that we experience as being correct." (Foundation, pp. 196-197) (In comparing the two processes, A and B, we must assume that each is the mirror image of the other.  Hence the one should not include any pleasures of anticipation unless the other includes a coresponding pleasure of recollection.)The bonum progressionis, then, would be a good situation corresponding to A, in our formulation above, and the malum regressus would be a bad situation corresponding to B.

Now let's see if we can apply this insight of Brentano to the question of the value of one's life.   A human life can be thought of as a whole the parts of which are its periods or phases.  It seems obvious that the value of the whole will depend on the values of the parts. 

But order comes into it as well.  Suppose lives L1 and L2 are such that the sums of the values of their constituent phases (however you care to individuate them) are  the same quantity of value, however this may be measured.  (There is also the serious question, which I set aside, of whether it even makes sense to speak of an objective measure of the value of a human life.) But whereas L1 begins well in childhood and adolescence but then deteriorates in quality, L2 begins poorly in childhood and adolescence and  gets better. 

If Brentano's bonum progressionis principle applies here, and I would say it does, then L2 is a more valuable life than L1 despite the fact that the sums of the values of their constituent phases are equal in value.  So we can say that the value of a life is more than the sum of the values of its parts when the life is ascending in value, but less than the sum of the values of its parts when the life is descending in value.

This may shed some light on why some people in old age (which I define as beginning at age 60), feel their lives to be not very valuable or satisfying while others in the same age cohort from similar backgrounds find their lives to be valuable and satisfying despite the obvious limitations that old age imposes.

The above analysis of course only scratches the surface.  Another thing to consider is that what is real and important to us is primarily what is real and important now.  The memories of past satisfactions are no match for the perceptions of present miseries.  So if the whole of one's life up to the present has been excellent while the present is miserable, the balance of good over evil cuts little or no ice.  But to explore this further is for another time. 

How Are Form and Matter Related in Compound Material Substances?

Favoring as I do constituent ontology, I am sympathetic to that type of constituent ontology which is hylomorphic ontological analysis, as practiced by Aristotelians, Thomists, et al.  The obscurity of such fundamental  concepts as form, matter, act, potency, substance, and others is, however, troubling. Let's see if we can make sense of the relation between form and matter in an artifact such as a bronze sphere. Now those of you who are ideologically committed to Thomism may bristle at an exposure of difficulties, but you should remember that philosophy is not ideology. The philosopher follows the argument to its conclusion whether it overturns his pet beliefs or supports them, or neither. He knows how to keep his ideological needs in check while pursuing pure inquiry.  If the inquiry terminates in an aporetic impasse, then so be it.

1. Although it perhaps requires arguing, I will here take it for granted that form and matter as these terms are used by Aristotle and his followers are items 'in the real order.' 'Item' is a maximally   noncommittal term in my lexicon: it commits me to very little. Anything in whatever category to which one can refer in any way  whatsoever is an item. 'Real' is that which exists whether or not it is an intentional object of an act of mind. So when I say that form and matter are items in the real order I simply mean that they are not projected by the mind: it is not as if bronze spheres and such have  form and matter only insofar as we interpret them as having form and matter. The bronze sphere is subject to hylomorphic (matter-form) analysis because the thing in reality is made up of form and matter.   'Projectivism' is off the table at least for the space of this post. I am thus assuming a version of realism and am viewing form and matter as distinct ontological constituents or 'principles' of compound   substances.

2. The foregoing implies that the proximate matter of the bronze sphere,  namely, the hunk of bronze itself, is a part of the bronze sphere.  After all, 'ontological constituent' is just a fancy way of saying  'ontological part.'  But an argument I now adapt from E. J. Lowe ("Form Without Matter" in Form and Matter: Themes in Contemporary  Metaphysics, ed. Oderberg, Blackwell 1999, p. 7) seems to show that  the notion that the proximate matter of a compound material substance is a part of it is problematic.  The argument runs as follows.

A. If the hunk of bronze composing the sphere is a part of the sphere, then either it is a proper part or it is an improper part, where an improper part of a whole W is a part of W that overlaps every part of   W.

B. The hunk of bronze is not an improper part since it is not identical to the bronze sphere. (One reason for this is that the persistence conditions are not the same: the piece of bronze will still exist if the sphere is flattened into a disk, but the sphere cannot survive such a deformation. Second, the two are modally discernible: the hunk of bronze is a hunk of bronze in every possible world in which it exists, but the hunk of bronze is not a sphere in every possible world in which it exists.)

C. The hunk of bronze is not a proper part of the bronze sphere since there is no part of the bronze sphere that it fails to overlap.

Therefore

D. The hunk of bronze is not a part of the bronze sphere.

Therefore

E. The composition of form and matter is not mereological. (Lowe, p. 7)

This raises the question of how exactly we are to understand form-matter composition. If the proximate matter of a substance cannot  be a part of it in any sense familiar to mereology, the form-matter composition is 'unmereological,' which is not necessarily an objection except that it raises the question of how exactly we are to understand this unmereological type of composition. This problem obviously extends to essence-existence composition.

3. Now let's look at the problem from the side of form. Could the spherical form of the bronze sphere be a part of it? A form is a principle of organization or arrangement, and it is not quite clear how an arrangement can be a part of the thing whose other parts it arranges. Lowe puts the point like this: ". . . the arrangement of certain parts cannot itself be one of those parts, as this would involve the very conception of an arrangement of parts in a fatal kind of impredicativity." (p. 7)

4. In sum, the difficulty is as follows. Form and matter are real 'principles' in compound substances. They are not projected or supplied by us. We can say that form and matter are ontological constituents of compound substances. This suggests that they are parts of compound substances. But we have just seen that they are not parts in any ordinary mereological sense. So this leaves us in the dark as to just what these 'principles' are and how they combine to constitute compound material substances.

Can the Chariot Take Us to the Land of No Self?

An abbreviated version of the following paper was published under the same title in The Proceedings of the Twenty-First World Congress of Philosophy, vol. 9, ed. Stephen Voss (Ankara, Turkey), 2006, pp. 29-33.

……………….

According to Buddhist ontology, every (samsaric) being  is impermanent, unsatisfactory, and devoid of self-nature.  Anicca, dukkha,  anatta: these are the famous three marks (tilakkhana) upon which the whole of Buddhism rests.  I would like to consider a well-known Buddhist argument for the third of these marks, that of anatta, an argument one could call ‘The Chariot.’  The argument aims to show that no (samsaric) being is a self, or has self-nature, or is a substance.  My thesis will be that, successful as this argument may be when applied to things other than ourselves, it fails when applied to ourselves.

Continue reading “Can the Chariot Take Us to the Land of No Self?”

Is the Difference Between a Fact and Its Constituents a Brute Difference?

Note to Steven Nemes:  Tell me if you find this totally clear, and if not, point out what is unclear.  Tell me whether you accept my overall argument.

The day before yesterday in conversation Steven Nemes presented a challenge  I am not sure I can meet.  I have maintained (in my book, in published articles, and in these pages) that the difference between a fact and its constituents cannot be a brute difference and must therefore have a ground or explanation.  But what exactly is my reasoning?

Consider a simple atomic fact of the form, a's being F.  This fact has two primary constituents, the individual a, and the monadic property F-ness, which a possesses contingently.  But surely there is more to the fact than these two primary constituents, and for at least two reasons.  I'll  mention just one, which I consider decisive:  the constituents can exist without the fact  existing.  The individual and the property could each exist without the former exemplifying the second.  This is so even if we assume that there are no propertyless individuals and no unexemplified properties.  Consider a world W which includes the facts Ga and Fb.  In W, a is propertied and F-ness is exemplified; hence there is no bar to saying that both exist in W.  But Fa does not exist in W.  So a fact is more than its primary constituents because they can exist without it existing.

A fact is not its constituents, but those constituents unified in a particular way.  Now if you try to secure fact-unity by introducing  one or more secondary constituents such  an exemplification relation, then you will ignite Bradley's regress.  For if the constituents include a, F-ness, and EX, then you still have the problem of their unity since the three can exist without constituting a fact.

So I take it as established that a fact is more than its constituents and therefore different from its constituents.  A fact is different from any one of its constituents, and also from all of them taken collectively, as a mereological sum, say.    The question is:  What is the ontological ground of the difference?  What is it that makes them different?  That they are different is plain.  I want to know what makes them different.  It won't do to say that one is a fact while the other is not since that simply underscores that they are different.  I'm on the hunt for a difference-maker.

To feel the force of the question consider what makes two different sets different.  If S1 and S2 are different sets, then it is reasonable to ask what makes them different, and one would presumably not accept the answer that they are just different, that the difference is a brute difference.  Let S1 be my singleton and S2 the set consisting of me and Nemes.  It would not do to say that they are just different.  We need a difference-maker.  In this case it is easy to specify: Nemes.  He is what makes S1 different from S2.  Both sets contain me, but only one contains him.  Generalizing, we can say that for sets at least,

DM. No difference without a difference-maker.

So I could argue that the difference between a fact and (the sum of) its constituents cannot be a brute difference because (i) there is no difference without a difference-maker and (ii) facts, sets, and sums, being complexes, are relevantly similar.  (I needn't hold that the numerical difference of two simples needs a difference-maker.) But why accept (DM) in full generality as applying to all types of wholes and parts?  Perhaps the principle, while applying to sets, does not apply to facts and their constituents.  How do I answer the person who argues that the difference is brute, a factum brutum, and that therefore (DM), taken in full generality, is false?  As we say in the trade, one man's modus ponens is another's modus tollens.

Can I show that there is a logical contradiction in maintaining that facts and their constituents just differ?  That was my strategy in the book on existence.  The strategy is to argue that without an external ground of unity — an external unifer — one lands in a contradiction, or rather cannot avoid a contradiction.  That the unifier, if there is one, must be external as opposed to internal is established by showing that otherwise a vicious infinite regress ensues of the Bradley-type.  I cover this ground in my book and in articles in mind-numbing detail; I cannot go over it again here.  But I will refer the reader to my 2010 Dialectica article  which discusses a fascinating proposal according to which unity is constituted by an internal infinite, but nonvicious, regress.  But for now I assume that the unifier, if there is one, must be external.  If there is one, then the difference between a fact and its constituents cannot be brute.  But why must there be a unifier?

Consider this aporetic triad:

1. Facts exist.
2. A fact is its constituents taken collectively.
3. A fact is not its constituents taken collectively.

What I want to argue is that facts exist, but that they are contradictory structures in the absence of an external unifier that removes the contradiction.  Since Nemes agrees with me about (1), I assume it for present purposes.  (The justification is via the truth-maker argument).

Note that (2) and (3) are logical contradictories, and yet each exerts a strong claim on our acceptance.  I have already argued for (3).  But (2) is also exceedingly plausible.  For if you  analyze a fact, what will you uncover?  Its constituents and nothing besides.  The unity of the constituents whereby it is a fact as opposed to a nonfact like a mereological sum eludes analysis.  The unity cannot be isolated or located within the fact.  For to locate it within the fact you would have to find it as one of the constituents.  And that you cannot do.

Note also that unity is not perceivable or in any way empirically detectable.  Consider a simple Bergmann-style or 'Iowa' example, a red round spot.  The redness and the roundness are perceivable, and the spot is perceivable.  But the spot's being red and round is not perceivable.  The existence of a fact is the unity of its constituents.  So what I am claiming is equivalent to claiming that existence is not perceivable, which seems right: existence is not an empirical feature like redness and roundness.

So when we consider a fact by itself, there seems to be nothing more to it than its constituents.

Each limb of the triad has  a strong claim on our acceptance, but they cannot all be true as formulated.  The contradiction can be removed if we ascend to a higher point of view and posit an external unifier.  What does that mean? 

Well, suppose there is a unifier U external to the fact and thus not identifiable with one or more of its primary or secondary constituents.  Suppose U brings together the constituents in the fact-making way.  U would then be the sought-for ground of the fact's unity.  The difference between a fact and its constituents could then be explained by saying that  the difference is due to U's 'activity':  U operates on the constituents to produce the fact.  Our original triad can then be replaced by the following all of whose limbs can be true:

1. Facts exist
2*. A fact, considered analytically, is its constituents taken collectively.
3.  A fact is not its constituents taken collectively.

This triad is consistent.  The limbs can all be true.  And I think we have excellent reason to say that each IS true.  The truthmaker argument vouches for (1).  (2*) looks to be true by definition.  The argumentation I gave for (3) above strikes me as well-night irresistible.

But if you accept the limbs of the modified triad, then you must accept that there is something external to facts which functions as their unifier.  Difficult questions about what U is and about whether U is unique and the same for all facts remain; but that U exists is 'fallout' from the modified triad.  For if each limb is true, then a fact's being more than its constituents can be accounted for only by appeal to an external unifier.

But how exactly does this show that the difference between a fact and its constituents is not a brute difference?   The move from the original to the modified triad is motivated by the laudable desire to avoid contradiction.  So my argument boils down to this:  If the difference is brute, then we get a logical contradiction. So the difference is not brute. 

But it all depends on whether or not there are facts.  If facts can be reasonably denied, then my reasoning to a unifer can be reasonably rejected.  But that's a whole other can of worms: the truthmaker argument.

Analytically considered, a fact is just its constituents.  But holistically considered it is not.  Unity eludes analysis, and yet without unities there would be nothing to analyze!  Analytic understanding operates under the aegis of two distinctions: whole/part, and complex/simple.  Analysis generates insight by reducing wholes to their parts, and complex parts to simpler and simpler parts, and possibly right down to ultimate simples (assuming that complexity does not extend 'all the way down.')  But analysis is a onesided epistemic procedure.  For again, without unities there would be nothing to analyze. To understand the being-unified of a unity therefore requires that we ascend to a  point of view external to the unity under analysis. 

Review : Modes of Being

Herewith, a little summary of part of what I have been arguing.  Most analytic philosophers would accept (A) but not (B):

A. There are kinds of existent but no kinds of existence.
B. There are kinds of existent and also kinds of existence.

I have been defending the intelligibility of (B) but without committing myself to any particular MOB doctrine.    I use 'modes of being' and 'kinds of existence' interchangeably. Of course I grant to Reinhardt Grossmann and others that the following inference is invalid:

1. K1 and K2 are dramatically different categories of existent
Ergo
2. Instances of K1 differ from instances of K2 in their mode of existence.

But an invalid argument can have a true conclusion.  So one can cheerfully grant the invalidity of the inference from (1) to (2) while insisting that there are categories  the respective members of which differ in their very mode of existence.  For example, although one cannot straightaway infer from the dramatic difference between (primary) substances and accidents that substances and accidents differ in their mode of existence, it is difficult to understand how they could fail to so differ.  After all, accidents depend on substances in that they cannot exist except in substances as modifications of substances, and this dependence is neither causal nor logical.  So I say it is existential dependence. 

Consider a bulge in a carpet.  The bulge cannot exist apart from the carpet whose bulge it is, whereas the carpet can exist without any bulge.  You might be tempted to say that bulge and carpet both simply exist, but that they are counterfactually related: Had the carpet not existed, the bulge would not have existed.  That's true, but what makes it true?  I say it is the fact of the bulge's existential dependence on the carpet.  Accidents exist in a different way than substances.

You could resist this conclusion by simply denying that there are substances and accidents.  Fine, but then I will shift to another example, wholes and parts, say.  Do you have the chutzpah to deny that there are wholes and parts?  Consider again the house made of bricks.  And now try this aporetic pentad on for size:

1. The house exists. 
2. The bricks exist. 
3. The house is not the bricks. 
4. The house is not something wholly diverse from the bricks, something in addition to it, something over and above it. 
5.  'Exist(s)' is univocal. 

The pentad is inconsistent: the limbs cannot all be true.  So what are you going to do?  Deny (1) like van Inwagen?  Maybe that is not crazy, but surely it is extreme.  (2), (3), and (4) are are undeniable.  So I say we ought to deny (5).  The house does not exist in the same way as the bricks.

 

Wholes, Parts, and Modes of Being

Do wholes and their parts exist in different ways?  The analytic establishment is hostile to modes of being, but its case is weak.  Indeed some establishmentarians make no case at all; they simply bluster and asseverate and beg the question.  I wonder how a member of the establishment would counter the following argument.  Consider a house made of bricks and nothing but bricks, and let's list some pertinent truths and see what follows.

1. The house exists.
2. The bricks exist.
3. The house is composed of the bricks, all of them, and of nothing else, and is not something wholly distinct from them or in addition to them.
4. The bricks can exist without the house, but the house cannot exist without the bricks.
5. The relation between the house and the bricks is neither causal nor logical.
Therefore
6. The house has a dependent mode of existence unlike the bricks. 

Peter van Inwagen, one of those establishmentarians who is hostile to the very idea of there being modes of being, will deny (1) as part of his general denial of artifacts.  If artifacts do not exist at all, then questions about how they exist, or in what way or mode, obviously lapse.  But it is evident to me that if we have to choose between denying artifacts and accepting modes of being, then we should accept modes of being!

(2) is undeniable as is (3):  it would obviously be absurd to think of the house as something over and above its constituents, as if it could exist even if they didn't.  The house is just the bricks arranged house-wise.  This is consistent with the truth of (1).  The fact that the house is just the bricks arranged house-wise does not entail that the house does not exist. 

(4) is equally evident and is just a consequence of (3).  I put the point modally but I could also make it temporally: before the Wise Pig assembled the bricks into a house fit to repel the huffing and puffing of the Big Bad Wolf, there was no house, but there were the bricks.

(5)  is also obviously true.  The bricks, taken individually or collectively, do not cause the house.  Now an Aristotelian may want to speak of the bricks as the 'material cause' of the house, but that is not the issue.  The issue is whether the bricks are the efficient cause of the cause.  The answer to that is obviously in the negative.  Nor are the bricks the cause of the house in the Humean sense of 'cause,' or in any modern sense of 'cause.'  For one thing, causation is standardly taken to relate events and neither a house nor a set or sum of its constituents is an event.

Could we say that the relation between bricks and house is logical? No. Logical relations relate propositions and neither the bricks nor the house is a proposition.  It is not a relation of supervenience either since supervenience relates properties and neither bricks nor house is a property.

But I hear an objection. 

I agree with you that the house is not identical to the bricks and that the former depends on the latter but not vice versa.  Why not just say that the two are related counterfactually?  Had the bricks not existed, the house would not have existed either.  Why not  say that and be done with it?  The house depends on the bricks but not conversely.  But the dependence of one existent on another does not seem to require that there are different modes of existence.

True, had the bricks not existed, the house would not have existed.    But what is the truth-maker of this counterfactual?  Your objection is superficial.  Obviously the house is not the bricks.  Obviously the house is dependent on the bricks.  I say that the house, as a whole of parts, exists-dependently.  You said nothing that refutes this.

We should also ask whether it makes sense to speak of a relation between bricks and house. It is certainly not an external relation if an external relation is one whose holding is accidental to the existence of its terms.  If brick A is on top of brick B, then they stand in a dyadic external relation: each can exist without standing in the relation, which is to say that their being related in this way is accidental to both of them.  But a house and its bricks are not externally related: the house cannot exist apart from its 'relation' to the bricks. 

The best thing to say here is that the house has a dependent mode of existence.  The house exists and the bricks exist, but the house exists in a different way than the bricks do.  If you deny this, then you are saying that the house and the bricks exist in the same way.  And what way is that?  Independently.  But it is obvious that the house does not exist independently of the bricks.

I will end by suggesting that van Inwagen's strange denial of artifacts is motivated by his failure to appreciate that there are modes of being.  For if there are no modes of being, and everything that exists exists in the same way, then one is forced to choose between saying either that the house exists independently of its constituent bricks or that the house does not exist at all.  Since van Inwagen perceives that it is absurd to say that the house exists independently of its constituent bricks, he is forced to say that it does not exist at all.

But if there are modes of being we can maintain, rather more sensibly, both that the house exists and that it does not exist independently of its constituent bricks.

 

Two Questions About the Bundle Theory Answered

On the bundle-of-universals theory of ordinary concrete particulars, such a particular is a bundle of its properties and its properties are universals.  This theory will appeal to those who, for various ontological and epistemological reasons, resist substratum theories and think of properties as universals.  Empiricists like Bertrand Russell, for example.  Powerful objections can be brought against the theory, but the following two questions suggested by  some comments of Peter Lupu  in an earlier thread are, I think, easily answered.

Q1.  How may universals does it take to constitute a particular?  Could there be a particular composed of only one or only two universals?

Q2.  We speak of particulars exemplifying properties.  But if a particular is a bundle of its properties, what could it mean to say of a particular that it exemplifies a property?

A1.  The answer is that it takes a complete set.  I take it to be a datum that the ordinary meso-particulars of Sellars' Manifest Image — let's stick with these — are completely determinate or complete in the following sense:

D1. X is complete =df for any predicate P, either x satisfies P or  x satisfies the complement of  P.

If predicates express properties, and properties are universals, and ordinary particulars are bundles of properties, then for each such particular there must be a complete set of universals.  For example, there cannot be a red rubber ball that has as constituents exactly three universals: being red, being made of rubber, being round.  For it must also have a determinate size, a determinate spatiotemporal location, and so on.  It has to be such that it is either covered with Fido's saliva or not so distinguished.  If it is red, then it must have a color; if it is round, it must have a shape, and so on.  This brings in further universals.  Whatever is, is complete.  That is a law of metaphysics, I should think.  Or perhaps it is only a law of phenomenological ontology, a law of the denizens of the Manifest Image.  (Let's not get into quantum mechanics.) 

A2.  If a particular is a bundle of universals, then it is a whole of parts, the universals being the (proper) parts, though not quite in the sense of classical mereology.  Why do I say that? Well, suppose you have a complete set of universals, and suppose further that they are logically and nomologically compossible.  It doesn't follow that they form a bundle.  But it does follow, by Unrestricted Summation, that there is a classical mereological sum of the universals.  So the bundle is not a sum.  Something more is required, namely, the contingent bundling to make of the universals a bundle, and thus a particular.

Now on a scheme like this there is no exemplification (EX) strictly speaking.  EX is an asymmetrical relation — or relational tie:  If x exemplifies P-ness, then it is not the case that P-ness exemplifies x.  Bundling is not exemplification because bundling is symmetrical: if U1 is bundled with U2, then U2 is bundled with U1.  So what do we mean when we say of a particular construed as a bundle that is has — or 'exemplifies' or 'instantiates' using these terms loosely — a property?  We mean that it has the property as a 'part.'   Not as a spatial or temporal part, but as an ontological part.  Thus:

D2. Bundle B has the property P-ness =df P=ness is an ontological 'part' of B.

Does this scheme bring problems in its train?  Of course!  They are for me to know and for you to figure out.

 

Definitions and Axioms of Classical Mereology

Is a wall or a brick house a whole of its parts?  Obviously — that's a pre-analytic datum.  But is it a sum of its parts?  I have been arguing, with no particular originality, in the negative.  I have been arguing that it is a big mistake to assume  that, just because y is a whole of the xs, that y is a sum of the xs. But it depends on what exactly is meant by 'sum.'  My point is well-taken if 'sum' is elliptical for 'classical mereological sum.'  But what does that mean?  Since 'classical mereological sum' is a technical term, it has all and only the meaning conferred upon it by the definitions and axioms of classical mereology.  I will now present what I take to be the essentials of classical mereology.  I will use 'sum' as short for 'classical mereological sum.'  Later we will look at neoclassical variants that result from tampering with the classical definitions and axioms.

If anything in what follows is original, it is probably a mistake on my part.  Feel free to correct me — but only if you know the subject matter.

I will take proper parthood and identity as primitives.  To simplify the exposition I will drop universal quantifiers.  They are there in spirit if not in letter.

D1. x is a PART of y =df x is a proper part of y or x = y.

D2. x OVERLAPS y =df there is a z such that z is part of x and z is part of y.

D3. x is DISJOINT from y =df it is not the case that x overlaps y.

D4. y is a SUM of the xs =df z overlaps y iff z overlaps one of the xs.

A1. Asymmetry of Proper Parthood.  If x is a proper part of y, then y is not a proper part of x.

A2. Transitivity of Proper Parthood.  If x is a proper part of y, and y is a proper part of z, then x is a proper part of z.

A3. Supplementation of Proper Parthood.  If x is a proper part of y, then there is a z such that z is a proper part of y and z is disjoint from x.

A4. Uniqueness of Summation.  If u is a sum of the xs and v is a sum of the xs, then u = v.

A5. Unrestricted Summation.  For any xs, there is a y such that y is a sum of the xs.

When I used the word 'sum' in previous posts, I intended that its meaning be not merely the meaning assigned to it by (D4), but the meaning assigned to it by (D4) in conjunction with the rest of the definitions and the axioms (not to mention the theorems that follow as logical consequences of the definitions and axioms). 

Extensionality is a feature of classical mereology.  I leave it as an exercise for the reader to derive Extensionality of Parthood  — if x and y are sums with the same proper parts, then x = y — as a theorem from the above.

 

A Closer Look at Material Composition and Modal Discernibility Arguments

(For David Brightly, whom I hope either to convince or argue to a standoff.)

Suppose God creates ex nihilo a bunch of TinkerToy pieces at time t suitable for assembly into various (toy) artifacts such as a house and a fort.  A unique classical mereological sum — call it 'TTS' — comes into existence 'automatically' at the instant of the creation ex nihilo of the TT pieces. (God doesn't have to do anything in addition to creating the TT pieces to bring TTS into existence.)   Suppose further that God at t  assembles the TT pieces (adding nothing and subtracting nothing) into a house.  Call this object 'TTH.'  So far we have: the pieces, their sum, and the house.  Now suppose that at t* (later than t) God annihilates all of the TT pieces.  This of course annihilates TTS and TTH.  During the interval from t to t* God maintains TTH in existence.

I set up the problem this way so as to exclude 'historical' and nonmodal considerations and thus to make the challenge tougher for my side.  Note that TTH and TTS are spatially coincident, temporally coincident, and such that every nonmodal property of the one is also a nonmodal property of the other.  Thus they have the same size, the same shape, the same weight, etc.  Surely the pressure is on to say that TTH = TTS?  Surely my opponents will come at me with their battle-cry, 'No difference without a difference-maker!'  There is no constituent of TTH that is not also a constituent of TTS.  So what could distinguish them?

Here is an argument that TTH and TTS are not identical:

1. NecId:  If x = y, then necessarily, x = y. 

2. If it is possible that ~(x = y), then ~(x = y). (From 1 by Contraposition)

3. If it is possible that TTS is not TTH, then TTS is not TTH. (From 2, by Universal Instantiation) 

4. It is possible that TTS is not TTH.  (God might have assembled the parts into a fort instead of a house or might have left them unassembled.)

5. TTS is not TTH. (From 3, 4 by Modus Ponens)

The gist of the argument is that if x = y, then they are identical in every possible world in which both of them exist.  But there are possible worlds in which TTS and TTH both exist but are not identical. (E.g., a world in which the pieces are assembled into a fort instead of a house.)  Therefore, TTS andf TTH are not identical.

If you are inclined to reject the argument, you must tell me which premise you reject.  Will it be (1)? Or will it be (4)? 

Your move, David.

 

Fregean Propositions, Unmereological Compositions, and Bradley’s Regress

Steven Nemes writes and I respond in blue:

I know you're in a bit of a mereology phase at the moment, but I figured I'd shoot this by you.

Mereology is the theory of parts and wholes.  Now propositions, whether Fregean or Russellian, are wholes of parts.  So mereology is not irrelevant to questions about the nature and existence of propositions.  The relevance, though, appears to be negative:  propositions are unmereological compositions, unmereological wholes.  That is to say, wholes that cannot be understood in terms of classical mereology.  They cannot be understood in these terms because of the problem of the unity of the proposition.  The problem is to specify what it is about a proposition that distinguishes it from a mere aggregate of its constituents and enables it to be either true or false.  No constituent of an atomic proposition is either true or false, and neither the mathematical set, nor the mereological sum, of the constituents of any such proposition is true or false; so what is it that makes a proposition a truth-bearer?  If you say that a special unifying constituent within propositions does the job,then you ignite Bradley's regress.  Whether or not it is vicious is a further question.  Richard Gaskin maintains the surprising view that Bradley's regress is "the metaphysical ground of the unity of  the proposition."  Far from being vicious, Bradley's regress is precisely that which "guarantees our ability to say anything at all."

For more on this topic, see my "Gaskin on the Unity of the Proposition," Dialectica vol. 64, no. 2 (June 2010), 265-277.  It is part of a five article symposium on the topic.

I am not sure if you believe in Fregean propositions or not. As for myself, I don't look favorably upon the idea of Fregean propositions because of the problem of Bradley's regress. (I am assuming propositions would be composite structured entities, built out of ontologically more basic parts, maybe the senses of the individual terms of the sentences that expresses it, so that the proposition expressed by "Minerva is irate" is a structured entity composed of the senses of "Minvera", "irate", etc.)

I provisionally accept, but ultimately reject, Fregean propositions.  What the devil does that mean?  It means that I think the arguments for them are quite powerful, but that if our system contains an absolute mind, then we can and must reduce Fregean propositions to contents or accuusatives of said mind.  Doing so allows us to solve the problem of the unity of the proposition.

By the way, what you say in parentheses is accurate and lucid. 

In your book, you offer a theistic strategy for solving the problem of Bradley's regress as applied to facts. I don't know that a theistic solution to the problem as applied to propositions works as smoothly because of the queer sort of things senses of individual terms of sentences are supposed to be. The building blocks of facts are universals, which are somewhat familiar entities; but the building blocks of propositions are senses like "Minerva" which are murky and mysterious things indeed. What the hell kind of a thing is a sense anyway?

A sense is a semantic intermediary, an abstract 'third-world' object neither in the mind nor in the realm of concreta, posited to explain certain linguistic phenomena.  One is the phenomenon of informative identity statements.  How are they possible?  'George Orwell is Eric Blair'  is an informative identity statement, unlike 'George Orwell is George Orwell.' How can the first be informative, how can it have what Frege calls cognitive value (Erkenntniswert), when it appears to be of the form a = b, a form all of the substitution-instances of which are false?  Long story short, Frege distinguishes between the sense and the referent of expressions. Accordingly, 'George Orwell' and 'Eric Blair' differ in sense but have the same referent.  The difference in sense explains the informativeness of the identity statement while the sameness of referent explains its truth.

Further, propositions are supposed to be necessarily existent; hence the individual building blocks of the propositions must also exist necessarily. But how could the senses expressed by "Minerva" or "Heidegger's wife", for instance, exist when those individuals do not? (This is the same sort of argument you give against haecceity properties conceived of as non-qualitative thisnesses.)

If proper names such as 'Heidegger' have irreducibly singular Fregean senses, then, as you well appreciate, my arguments against haecceity properties (nonqualitative thisnesses) kick in.  It is particularly difficult to understand how a proper name could express an irreducibly singular Fregean sense when the name in question lacks a referent.  For if irreducibly singular, then the sense is not constructible from general senses by an analog of propositional conjunction.  So one is forced to say that the sense of 'Minerva' is the property of being identical to Minerva.  But since there is no such individual, there is no such property.  Identity-with-Minerva collapses into Identity-with- . . . nothing!  Pace Plantinga, of course.

In the case of identity-with-Heidegger, surely this property, if it exists at all, exists iff Heidegger does.  Given that Heidegger is a contingent being, his haecceity is as well.  And that conflicts with the notion that propositions are necessary beings.  Well, I suppose one could try the idea the some propositions are contingent beings.

Are there any solutions to the former problem (which you've blogged and written about before!) you think are promising? Further, what do you think of the second problem?

Perhaps you think the second problem can be sidestepped by saying that "Heidegger's wife" is just shorthand for some longer description, e.g. "the woman who was married to the man who wrote a book that began with the sentence '…'". I don't know that it is so easy, because that sentence itself makes reference to things that are contingently existent (women, men, books, sentences, marriage…).

Yes,all those things are contingent.  But that by itself does not cause a problem.  The problem is with the notion that proper names are definite descriptions in disguise.  If the very sense of 'Ben Franklin' is supplied by 'the inventor of bifocals' (to use Kripke's example), then the true 'Ben Franklin might not have invented bifocals' boils down to the necessarily false 'The inventor of bifocals might not have invented bifocals.'  (But note the ambiguity of the preceding sentence; I mean the definite description to be taken attributively not referentially.)

Varzi, Sums, and Wholes

Achille C. Varzi, "The Extensionality of Parthood and Composition," The Philosophical Quarterly 58 (2008), p. 109:

Suppose we have a house made of Tinkertoy pieces.  Then the house qualifies as a sum of those pieces: each piece is part of the house and each part of the house overlaps at least one of the pieces . . . . Are there other things that qualify as the sums of those pieces?  UC says there aren't; the house is the only candidate: it is the sum of those pieces.

UC is Uniqueness of Composition: 

UC  If x and y are sums of the same things, then x = y,

where

(1) x is a sum of the zs =df The zs are all parts of x and every part of x has a part in common with at least one ofthe zs. 

Perhaps commenter John, who knows some mereology and the relevant literature on material composition, can help me understand this.  What I don't understand is what entitles Varzi to assume that the Tinkertoy house — 'TTH' to give it a name — is identical to a classical mereological sum.  I do not deny that there is a sum of the parts of TTH.  And I do not doubt that this sum is unique.  Let us name this sum 'TTS.'  (I assume that names are Kripkean rigid designators.)  What I do not understand is the justification of the assumption, made near the beginning of his paper, of the identity of TTH and TTS.  TTH is of course a whole of parts.  But it doesn't straightaway follow that TTH is a sum of parts.

Please note that 'sum' is a technical term, one whose meaning is exactly the meaning it derives from the definitions and axioms of classical mereology.  'Whole' is a term of ordinary language whose meaning depends on context.  It seems to me that one cannot just assume that a given whole of parts is identical to a mereological sum of those same parts.

I am not denying that it might be useful for some purposes  to think of material objects like TTH as sums, but by the same token it might be useful to think of material objects as (mathematical)  sets of their parts.  But surely it would be a mistake to identify TTH with a set of its parts.  For one thing, sets are abstract while material objects are concrete.  For another, proper parthood is transitive while set-theoretic elementhood is not transitive. 

Of course, sums are not sets.  A sum of concreta is itself concrete whereas a set of concreta is itself abstract.  My point is that, just as we cannot assume that that TTH is identical to a set, we cannot assume that TTH is identical to a sum.

What is the 'dialectical situation' when it comes to the dispute between those who maintain that TTH = TTS and those who deny this identity?

It seems to me that the burden of proof rests on those who, like Varzi, identify material objects like TTH with sums especially given the arguments against the identity.  Here is one argument. (a) Taking TTH apart would destroy it, (b) but would not destroy TTS.  Therefore, (c) TTH is not identical to TTS.  This argument relies on the wholly unproblematic Indiscernibility of Identicals as a tacit premise:  If x = y, then whatever is true of x is true of y, and vice versa.  Because something is true of TTH — namely, that taking it apart would destroy it — that is not true of TTS, TTH cannot be identical to TTS.

The simplicity and clarity of modal discernibility arguments like this one cast grave doubt on the opening assumption that TTH is a sum.  I am not saying that Varzi and Co. have no response to the argument; they do.  My point is that their response comes too late dialectically speaking.  If you know what a sum is, you know that the identity is dubious from the outset: the discernibility arguments merely make the dubiousness explicit. Responding to these arguments strikes me as too little too late; what the identity theorist needs to do is justify his intitial assumption as soon as he makes it.

My main question, then, is this.  What justifies the initial assumption that material particulars such as Tinkertoy houses are mereological sums?  It cannot be that they are wholes of parts, for a whole needn't be a sum.  TTH is a whole but it is not a sum.  It is not a sum because a sum is a collection that is neutral with respect to the arrangement or interrelation of its parts, whereas it is essential to TTH that its parts be arranged house-wise.

 

Four-Dimensionalism to the Rescue?

Let us return to that impressive product of porcine ingenuity, Brick House.  Brick House, whose completion by the Wise Pig occurred on Friday, is composed entirely of the 10,000 Tuesday Bricks.  I grant that there is a sum, call it 'Brick Sum,' that is the classical mereological sum of the Tuesday Bricks.  Brick Sum is 'generated' — if you care to put it that way — by Unrestricted Composition, the classical axiom which states that "Whenever there are some things, then there exists a fusion [sum] of those things." (D. Lewis, Parts of Classes, p. 74)  I also grant that Brick Sum is unique by Uniqueness of Composition according to which "It never happens that the same things have two different fusions [sums]." (Ibid.)  But I deny Lewis' Composition as Identity.  Accordingly, Brick Sum cannot be identical to the Tuesday Bricks.   After all, it is one while they are many.

Now the question I am debating with commenter John is whether Brick House is identical to Brick Sum.  This ought not be confused with the question whether Brick House is identical to the Tuesday Bricks.  This second question has an easy negative answer inasmuch as the former is one while the latter are many.  Clearly, one thing cannot be many things.

The question, then, is whether Brick House is identical to Brick Sum.  Here is a reason to think that they are not identical.  Brick Sum exists regardless of the arrangement of its parts: they can be scattered throughout the land; they can be piled up in one place; they can be moving away from each other; they can be arranged to form a wall, or a corral, or a house, or whatever.  All of this without prejudice to the existence and the identity of Brick Sum.  Now suppose Hezbollah Wolf, a 'porcicide' bomber, enters Brick House and blows it and himself up at time t on Friday evening. At time t* later than t, Brick Sum still exists while Brick House does not.  This shows that they cannot be identical; for if they were identical, then the destruction of Brick House would be the destruction of Brick Sum. 

This argument, however, rests on an assumption, namely, that Brick Sum exists both at t and at t*.   This won't be true if Four Dimensionalism is true.  If bricks and houses are occurrents rather than continuants, if they are composed of temporal parts, then we cannot say, strictly and philosophically, that Brick Sum at t still exists at t*.  And if we cannot say this, then the above argument fails.

But all is not lost since there remains a modal consideration.  Brick House and Brick Sum both exist at time t in the actual world.  But there are plenty of possible worlds in which, at t, the latter exists but not the former.  Thus it might have been the case at t that the bricks were arranged corral-wise rather than house-wise.  So Brick Sum has a property that Brick House lacks, namely, the modal property of being such that its parts could have been arranged in non-house-wise fashion.  Therefore, by the Indiscernibility of Identicals, Brick House is not identical to Brick Sum.

So even if the historical discernibility argument fails on Four Dimensionalism, the modal discernibility argument seems to work even assuming Four Dimensionalism.

Please note that my thesis is not that Brick House is a sum that violates Uniqueness of Composition, but that Brick House is not a classical mereological sum.    If Brick House were a sum, then it would be Brick Sum.  But I have just argued that it cannot be Brick Sum.  So it cannot identified with any classical sum.  It is a whole of parts all right, but an unmereological whole.  What does that mean?  It means that it is a whole that cannot be adequately understood using only the resources of classical mereology.

 

Van Inwagen on Arbitrary Undetached Parts

In order to get clear about Dion-Theon and related identity puzzles we need to get clear about the Doctrine of Arbitrary Undetached Parts (DAUP) and see what bearing it has on the puzzles. Peter van Inwagen provides the following statement of DAUP:

For every material object M, if R is the region of space occupied by M at time t, and if sub-R is any occupiable sub-region of R whatever, there exists a material object that occupies the region sub-R at t. ("The Doctrine of Arbitrary Undetached Parts" in Ontology, Identity, and Modality, CUP, 2001, 75.) 

Suppose I am smoking a cigar. DAUP implies that the middle two-thirds of the cigar is just as much a concrete material object as the whole cigar. This middle two-thirds is an undetached part of the cigar, but also an arbitrary undetached part since I could have arbitrarily selected uncountably many other lengths such as the middle three-fourths. Applied to Tibbles the cat, DAUP implies that Tibbles-minus-one-hair is just as full-fledged a material object as Tibbles. Van Inwagen maintains that DAUP is false.

I will reconstruct van Inwagen's argument for the falsity of DAUP as clearly as I can. Consider Descartes and his left leg L. To keep it simple, we make the unCartesian assumption that Descartes is just a live body. DAUP implies that L is a material object as much as Descartes himself. DAUP also implies that there is a material object we can call D-minus. This is Descartes-minus-L. It is obvious that Descartes and D-minus are not the same. (For one thing, they are differently shaped. For another, they are 'differently abled' in PC jargon.) At time t, D-minus and L are undetached nonoverlapping proper parts of Descartes, and both are just as much full-fledged material objects as Descartes himself is.

Now suppose a little later, at t*, L becomes detached from D-minus. In plain English, Descartes at t* loses his leg. (To avoid certain complications, we also assume that the leg is not only removed but also annihilated.) Does D-minus still exist after t*?  Van Inwagen thinks it is obvious that D-minus does exist after the operation at t*. DAUP implies that the undetached parts of material objects are themselves material objects. So D-minus prior to t* is a material object. Its becoming detached from L does not affect D-minus or its parts, and if the separation of L from D-minus were to cause D-minus to cease to exist, then, van Inwagen claims, D-minus could not properly be called a material object. Descartes himself also exists after the operation at t*. Surely one can survive the loss of a leg. So after t* both D-minus and Descartes exist. But if they both exist, then they are identical. For otherwise there would be two material objects having exactly the same size, shape, position, mass, velocity, etc., and that is impossible.

In sum, at time t, D-minus and Descartes are not identical, while at the later time t* they are identical. The result is the following inconsistent tetrad:

D-minus before t* = D-minus after t*

D-minus after t* = Descartes after t*

Descartes after t* = Descartes before t*

It is not the case that  D-minus before t* = Descartes before t*

The first three propositions entail the negation of the fourth. From this contradiction van Inwagen infers that there never was any such thing as D-minus. If so, then DAUP is false. But as van Inwagen realizes, his refutation of DAUP has a counterintuitive consequence, namely, that L does not exist either: there never was any such thing as Descartes' left leg. For it seems obvious that D-minus and L stand or fall together, to repeat van Inwagen's pun.

That is, D-minus exists if and only if L exists, and D-minus does not exist if and only if L does not exist. D-minus is an arbitrary undetached proper part of Descartes if and only if L is an arbitrary undetached proper part of Descartes. At this point, I think it becomes clear that van Inwagen's solution to the Dion/Theon or Descartes/D-minus puzzle is not compelling. He solves the puzzle by denying that there was ever any such material object as D-minus. But if there was no D-minus, then there was never any such material object as Descartes' left leg. It is obvious, however, that there was such a material object as Descartes' left leg L. So how could it be maintained that there was no such object as Descartes-minus? Van Inwagen makes it clear (p. 82, n. 12) that he does not deny that there are undetached parts. What I take him to be denying is that, for any P and O, where P is an undetached part of material object O, there is a complementary proper part of O, O-minus-P. So perhaps van Inwagen can say that L is a non-arbitrary undetached part of Descartes and that this is consistent with there being no D-minus. If so, he would have to reject the following supplementation principle of mereology which seems intuitively sound:

For any x, y, z, if x is a proper part of y, then there exists a z such that z is a part of y and z does not overlap x , where x overlaps y =df there exists a z such that z is a part of x and z is a part of y.

What the above supplementation principle says is that you cannot have a whole with only one proper part. Every whole having a proper part has a second proper part that supplements or complements the first so as to constitute a whole. Now Descartes' leg is a proper part of Descartes. So the existence of D-minus falls out of the supplementation principle.

It seems, then, that van Inwagen's rejection of DAUP  issues in a dilemma.  If there is no such object as Descartes minus his left leg, then there is no such object as Descartes' left leg, which is highly counterintuitive, to put it mildly.  But if van Inwagen holds onto the left leg, then it seems his must reject the seemingly obvious supplementation principle lately mentioned.

My interim conclusion is that van Inwagen's solution to the Descartes/D-minus puzzle by rejection of DAUP is not compelling.

Can a Mereological Sum Change its Parts?

This post is an attempt to understand and evaluate Peter van Inwagen's "Can Mereological Sums Change Their Parts," J. Phil. (December 2006), 614-630.  A preprint is available online here.

The Wise Pig and the Brick House: My Take

On Tuesday the Wise Pig  takes delivery of 10,000 bricks.  On the following Friday he completes construction of a house made of exactly these bricks and nothing else.  Call the bricks in question the 'Tuesday bricks.'  I would 'assay' the situation as follows.  On Tuesday there are some unassembled bricks laying about the building site.  By Unrestricted Composition, these bricks compose a classical mereological sum.  Call this sum 'Brick Sum.'  (To save keystrokes I will write 'sum' for 'classical mereological sum.' ) By Uniqueness of Composition, there is exactly one sum that the Tuesday bricks compose.  On Friday, both the Tuesday bricks and their (unique) sum exist.  But as I see it, the Brick House is identical neither to the Tuesday bricks nor to their sum.  Thus I deny that the Brick House is identical to the sum of the things that compose it. I give two arguments for this non-identity.

Nonmodal 'Historical' Argument:  Brick Sum has a property that Brick House does not have, namely the property of existing on Tuesday.  Therefore, by the Indiscernibility of Identicals, Brick Sum is not identical to Brick House.

Modal Argument:  Suppose that the actual world is such that Brick Sum and Brick House always existed, exist now, and always will exist:  every time t is such that both exist at t.  This does not alter the plain fact that the house depends for its existence on the bricks, while the bricks do not depend for their existence on the house.  Thus there are possible worlds in which Brick Sum exists but Brick House does not.  (Note that Brick Sum exists 'automatically' given the existence of the bricks.) These worlds are simply the worlds in which the bricks exist but in an unassembled state.  So Brick Sum has a property that Brick House does not have, namely, the modal property of being possibly such as to exist without composing a house.  Therefore, by the Indiscernibility of Identicals, Brick Sum is not identical to Brick House.

In sum (pardon the pun!), The Brick House is not a mereological sum.  (If it were, it would have existed on Tuesday as a load of bricks, which is absurd.)  This is not to say that there is no sum 'corresponding' to the Brick House: there is.  It is just that this sum — Brick Sum — is not identical to Brick House.  So what I am saying implies no rejection of Unrestricted Composition.  The point is rather that a material artifact such as a house cannot be identified with the mereological sum of the things it is made of.  This is because sums abstract or prescind from the mutual relations of parts in virtue of which parts form what we might call  'integral wholes' as opposed to a mere mereological sums.  Unassembled bricks do not a brick house make: you have to assemble them properly.  And the assembly, however you want to assay it, is an added ontological ingredient that escapes consideration by a general purely formal part-whole theory such as classical mereology.

I assume with van Inwagen that Brick House can lose a brick (or gain a brick)  without prejudice to its identity.  But, contra van Inwagen, I do not take this to imply that mereological sums can gain or lose parts.  And this for the simple reason that Brick House and things like it are not identical to sums of the things that compose them.  I would say, pace van Inwagen, that mereological sums can no more gain or lose parts than (mathematical) sets can gain or lose elements.

The Wise Pig and the Brick House: Van Inwagen's Take

I agree with van Inwagen that "The Tuesday bricks are all parts of the Brick House and every part of the Brick House overlaps at least one of the Tuesday bricks." (616-617)  But he takes this obvious truth to imply that " . . . 'a merelogical sum' is the obvious thing to call something of which the Tuesday Bricks are all parts and each of whose parts overlaps at least one of the Tuesday Bricks." (617)  Well, he can call it that but only if he uses 'mereological sum' in a way different that the way it is used in classical mereology.

Now if we acquiesce in van Inwagen's usage, and we grant that things like houses can change their parts, then it follows that mereological sums can change their parts.  But why should we acquiesce in van Inwagen's usage of 'mereological sum'?

Is Everything a Mereological Sum?

As I use 'mereological sum,' not everything is such a sum.  The Brick House is not a sum.  It is no more a sum than it is a set.  There are sums and there are sets, but not everything is a sum just as not everything is a set.  There is a set consisting of the Tuesday Bricks, and there is a singleton set of the Brick House.  But neither of these sets is identical to the Brick House.  Neither of them has anything to fear from the pulmonary exertions of the Big Bad Wolf — not because they are so strong, but because they are abstract objects removed from the flux and shove of the causal order.  Sums of concreta, unlike sets of concreta,  are themselves concrete — but the Brick House is not a sum.  Van Inwagen disagrees.  For him, "Everything is a mereological sum." (618)

His argument for this surprising claim is roughly as follows. PvI's presentation is tedious and technical but I think I will not be misrepresenting him if I sum up the gist of it as follows:

1. Everything, whether simple or composite, has parts.  (This is a consequence of the following definition: x is a part of y =df x is a proper part of y or x = y.  Because everything is self-identical, everything has itself as a part, an improper part to be sure, but a part nonetheless. Therefore:

2. Everything is a mereological sum of its parts.  Therefore:

3. Everything is a mereological sum. Therefore:

4. ". . . mereological sums are not a special sort of object." (622)  In this respect they are unlike sets."'Mereological sum' is not a useful stand-alone general term." (622) 'Set' is.

What's At Issue Here?

I confess to not being clear about what exactly is at issue here.  One could of course use 'mereological sum' in the way that van Inwagen proposes, a way that implies that everything is a mereological sum, and that implies that there is no conceptual confusion in the notion of a mereological sum changing its parts.   But why adopt this usage?  How does it help us in the understanding of material composition?

What am I missing?

 

Van Inwagen Contra Lewis on Composition as Identity

Modifying an example employed by Donald Baxter and David Lewis, suppose I own a parcel of land A consisting of exactly two adjoining lots B and C. It would be an insane boast were I to claim to own three parcels of land, B, C, and A. That would be 'double-counting': I count A as if it is a parcel in addition to B and C, when in fact all the land in A is in B and C taken together. Lewis, rejecting 'double-counting,' will say that A = (B + C). Thus A is identical to what composes it. This is an instance of the thesis of composition as identity.

Or suppose there are some cats.  Then, by Unrestricted Composition ("Whenever there are some things, then there exists a fusion [sum] of those things"), there exists a sum that the cats compose.  But by Composition as Identity, this sum is identical to what compose it, taken collectively, not distributively.  Thus the sum is the cats, and they are it.  I agree with van Inwagen that this notion of Composition as Identity is very hard to make sense of, for reasons at the end of the above link.  But Peter van Inwagen's argument against Composition as Identity strikes me as equally puzzling.  Van Inwagen argues against it as follows:

Suppose that there exists nothing but my big parcel of land and such parts as it may have. And suppose it has no proper parts but the six small parcels. . . . Suppose that we have a bunch of sentences containing quantifiers, and that we want to determine their truth-values: 'ExEyEz(y is a part of x & z is a part of x & y is not the same size as z)'; that sort of thing. How many items in our domain of quantification? Seven, right? That is, there are seven objects, and not six objects or one object, that are possible values of our variables, and that we must take account of when we are determining the truth-value of our sentences. ("Composition as Identity," Philosophical Perspectives 8 (1994), p. 213)

In terms of my original example, Lewis is saying that A is identical to what composes it. Van Inwagen is denying this and saying that A is not identical to what composes it. His reason is that there must be at least three entities in the domain of quantification to make the relevant quantified sentences true. A is therefore a third entity in addition to B and C. It is this that I don't understand. Van Inwagen's argument strikes me as a non sequitur. Or perhaps I just don't understand it. Consider this obviously true quantified sentence:

1. For any x, there is a y such that x = y.

(1) features two distinct bound variables, 'x'and 'y.' But it does not follow that there must be two entities in the domain of quantification for (1) to be true. It might be that the domain consists of exactly one individual a. Applying Existential Instantiation to (1), we get

 2. a = a.

Relative to a domain consisting of a alone, (1) and (2) are logically equivalent. From the fact that there are two variables in (1), it does not follow that there are two entities in the domain relative to which (1) is evaluated. Now consider

3. There is an x, y and z such that x is a proper part of z & y is a proper part of z.

(3) contains three distinct variables, but it does not follow that the domain of quantification must contain three distinct entities for (3) to be true. Suppose that Lewis is right, and that A = (B + C). It will then be possible to existentially instantiate (3) using only two entities, thus:

4. B is a proper part of (B + C) & C is a proper part of (B + C).

If van Inwagen thinks that a quantified sentence in n variables can be evaluated only relative to a domain containing n entities (or values), then I refute him using (1) above. If van Inwagen holds that (3) requires three entities for its evaluation, then I say he has simply begged the question against Lewis by assuming that (B + C) is not identical to A. It is important not to confuse the level of representation with the level of reality. That there are two different names for a thing does not imply that there are really two things. ('Hesperus' and 'Phosphorus' both name the same planet, Venus, to coin an example.) Likewise, the fact that there are two distinct bound variables at the level of linguistic representation does not entail that at the level of reality there are two distinct values. There might be or there might not be.

So I cannot see that van Inwagen has given me any reason to think that A is a third entity in addition to B and C. But it doesn't follow that I think that Lewis' thesis is correct. Both are wrong.  Here is the problem. 'A = (B + C)' is the logical contradictory of '~ (A = (B + C)).' Thus one will be tempted to plump for one or the other limb of the contradiction. But there are reasons to reject both limbs.

Surely A is more than the mereological sum of B and C. This is because A involves a further ontological ingredient, namely, the connectedness or adjacency of B and C. To put it another way, A is a unity of its parts, not a pure manifold. The Lewis approach leaves out unity. Suppose B is in Arizona and C is in Ohio. Then the mereological sum (B + C) automatically exists, by Unrestricted Composition.   But this scattered object is not identical to the object which is B-adjoining-C. On the latter I can build a house whose square footage is greater than that of B or C; on the scattered object I cannot. But A is not a third entity. It is obvious that A is not wholly distinct from B and C inasmuch as A is composed of B and C as its sole nonoverlapping proper parts. Analysis of A discloses nothing other than B and C.  But neither is A identical to  B + C.

In short, both limbs of the contradiction are unacceptable. How then are we to avoid the contradiction?

Perhaps we can say that A is identical,  not to the sum B + C, but to B-adjoining-C, an unmereological whole.  But this needs explaining, doesn't  it?