A
Polar Concept Argument for the Existence of Abstracta
preprint
Paul Franceschi
University of Corsica
revised October 2003
p.franceschi@univ-corse.fr
http://www.univ-corse.fr/~franceschi
ABSTRACT I present
a polar concept argument for the existence of abstract objects. After recalling
the fundamentals concerning the debate about the existence of abstracta, I
present in a detailed way the argument for the existence of abstracta. I offer
two different variations of the argument: one, deductive and the other,
inductive. The argument rests primarily on the fact that our universe is
well-balanced. This well-balanced property results from the fact that all
instantiable polar dualities are instantiated. Hence, the abstract pole of the
abstract/concrete duality must also be exemplified. Lastly, I review several
objections that can be raised against the present argument.
There are several famous
problems about abstract entities. One of them is whether there exist any
abstract objects. A second issue is concerned with the definition of which
sorts of entities are genuinely abstract. A third issue relates to whether the
abstract/concrete duality is exhaustive or not. The purpose of this paper is to
address the first of these issues and to describe a polar concept argument that
entails the existence of abstracta. Before stating the argument in detail and
reviewing several objections that can be raised against it, it is worth
recalling first the fundamentals of the debate about the existence of
abstracta.
1. The
debate about the existence of abstracta
Let us recall preliminarily
the main lines of the issue of whether there exist abstract objects[1].
This latter problem rests primarily on the abstract/concrete distinction.
Uncontroversially, the following objects are considered as abstracta: the
natural numbers, the cosine function, the Pythagorean theorem. For this reason,
I shall only be concerned in what follows with paradigm abstracta, i.e. natural
numbers, setting aside other sorts of entities whose status is controversial.
On the other hand, an instance of jay or of an oak-tree, the mountain in front
of me, the sun, our galaxy are paradigmatically classified as concrete objects.
In this context, concreta are considered as existent objects. But at this
stage, agreement stops. In effect, by contrast, the mere existence of abstracta
is at issue. Do abstract objects truly exist? There are two main philosophical
answers to this latter question. On the one hand, some philosophers simply deny
the existence of abstracta. According to the corresponding line of thought,
only concrete objects exist in our universe, and abstract concepts are a mere
product of our brain circuitry. Thus, natural numbers, the sine function, and
so on. which are considered as paradigm cases of abstracta, exist only in our
mind. The view that denies the existence of abstract objets is nominalism.
On the other
hand, according to a line of thought originating from Plato, abstract objects
do truly exist. According to platonism,
abstracta have an existence of their own, in the same way as concreta do exist.
In addition, abstracta are standardly considered as having no spatiotemporal
position, in contrast to concreta which possess a given position in space and
time.
The main argument
for abstracta is the Quine-Putnam indispensability
argument.[2] Its first
premise is that we should be committed to the existence of all entities that
are indispensable to our best scientific theories. From the consideration that
natural numbers are indispensable to these latter scientific theories, it
follows that we should be committed to the existence of natural numbers. The
indispensability argument is controversial and has notably led to important
objections raised by Hartry Field (1980), Penelope Maddy (1992) and Elliott
Sober (1993). Without entering into the details of these criticisms, I will
offer here a different line of argument for abstract objects than the
indispensability argument.
2. The polar concept argument for the existence
of abstracta
In what follows, I borrow
the expression 'polar concept argument' from the characterisation of Ryle's
argument against scepticism[3]
(1960) provided by Anthony Grayling (1995, pp. 49-50). Grayling describes
Ryle's argument in the following terms:
The point can be simply illustrated by a consideration of Gilbert Ryle's attempt to refute the argument from error by a 'polar concept' argument. There cannot be counterfeit coins, Ryle observes, unless there are genuine ones, nor crooked paths unless there are straight paths, nor tall men unless there are short men. Many concepts come in pairs which are polar opposites of one another, and these conceptual polarities are such that one cannot grasp either pole unless one grasps its opposite at the same time. Now error and 'getting it right' are conceptual polarities. If one understands the concept of error, one understands the concept of getting it right. But to understand this latter concept is to be able to apply it. So our very grasp of the concept of error implies that we sometimes get things right.
Grayling characterises thus
as a polar concept argument the
argument used by Gilbert Ryle to refute the argument from error, which takes
place in the debate against scepticism. The argument from error puts in
parallel two types of situations. On the one hand, it appears that we often
mistakenly have some knowledge that comes from perceptual experience. But these
latter situations, argues the sceptic, are indistinguishable from present situations
in which we have some knowledge that stem from our current perceptual
experiences. Therefore, concludes the sceptic, our present knowledge could also
be mistaken. According to Ryle, the argument from error is inconclusive, since
'getting it right' and 'error' are opposites and originate from the same
duality. Hence, Ryle pursues, whenever one grasps the concept of 'error', one
also grasps the opposite concept of 'getting it right'. A further step states
that to understand the corresponding concept is tantamount to being able to
apply it in practice. And this finally undermines the conclusion of the
argument from error. I shall not discuss here whether Ryle's argument is valid
or not. Rather, my concern will be with showing that an analogous polar concept
argument can be used in support of the existence of abstracta.
The polar concept
argument for the existence of abstracta can be sketched informally as follows.
Begin with the fact that our universe is well-balanced. A summary analysis
reveals that this well-balanced property is exemplified many times. Consider
for example the existence, at a macroscopic level, of very large objects such
as stars, supernovae or galaxies. Contrast now with the existence, at a
microscopic level, of very small objects such as atoms or molecules. This
illustrates how our universe is well-balanced with regard to the large/small
duality. Now it appears that numerous other polar opposites are also
instantiated in our universe. Consider how both poles of the hot/cold duality are
exemplified. It suffices to consider the existence, on the one hand, of hot
objects such as stars, and on the other hand, of cold objects such as brown
dwarfs, dead stars or asteroids. This shows how our universe is also
well-balanced with regard to the hot/cold duality. Now consider how many
dualities such as attractive/repulsive, static/dynamic, bright/dark,
positive/negative, neutral/charged, visible/invisible, and so on, are also
instantiated. At this step, it is worth considering the case of the abstract/concrete
duality. There is uncontroversial evidence that concrete objects exist in our universe. Now the necessary
well-balance of our universe with regard to the abstract/concrete duality also
entails the necessary existence of abstract objects.
At this step, for
the sake of accuracy, a few definitions are needed. Let us begin with polar opposites. Intuitive though it is,
the notion of polar opposites needs in effect clarifying. Paradigm examples of
polar opposites are positive/negative, small/large, static/dynamic,
internal/external, and so on. But let us provide an explicit definition. To
begin with, polar opposites are polar concepts, i.e. concepts which
intuitively come in pairs, and are such that each one is defined as the
opposite of the other. For example, internal
can be defined as the opposite of external,
while symmetrically external can also
be defined as the opposite of internal.
Both poles are the contrary of one another. In a sense, there is no primitive
notion: neither poles of the A/Ā duality can be regarded as the primitive
notion.
Let us stress,
second, that both poles of a given duality are simple qualities, in opposition to composite qualities. The
distinction between simple and composite qualities can be drawn as follows. Let
A1, A2 be simple qualities. Now A1 Ù A2, A1
Ú A2
are composite qualities. To give an example, small, static, positive are simple qualities, while small and static, small and positive, static and positive, small and static and positive
are composite qualities. A more general definition is then as follows: B1,
B2 being simple or composite qualities, B1 Ù B2, B1
Ú B2
are composite qualities. Incidentally, this also casts light on the reason why
red/non-red, blue/non-blue cannot be considered polar opposites. For non-red can be defined as violet Ú indigo Ú blue Ú green Ú yellow Ú orange Ú white Ú black.
It is worth
mentioning, third, that polar opposites are neutral
concepts, i.e. neither meliorative nor pejorative. Accordingly, large, small, external, internal, concrete, abstract, and
so on, are neutral polar concepts, to the difference of such concepts as beautiful, ugly, courageous, which
are non-neutral.
Given this
definition, we are in a position to distinguish polar opposites from vague objects. It should be noticed
first that polar opposites and vague objects share some common features. In
effect, vague objects come in pairs, in the same way as polar opposites. In
addition, vague concepts are classically viewed as possessing an extension and
an anti-extension, which are mutually exclusive. Such a feature is also shared
by polar opposites. But let us stress now the differences between the two
categories. A first difference (i) consists in the fact that the extension and
the anti-extension of vague concepts are not jointly exhaustive, for they admit
of borderline cases (and also borderline cases of borderlines cases, and so on,
thus giving rise to the hierarchy of higher-order vagueness), which constitute
a penumbral zone. In contrast however, polar contraries do not necessarily
possess this latter feature. In effect, polar opposites can be either
exhaustive or non-exhaustive. For example, the abstract/concrete duality is
intuitively exhaustive, for there does not seem to exist objects that are
neither abstract nor concrete. Now the same goes for the vague/precise duality:
intuitively, there does not exist objects which are neither precise nor vague
and pertain to an intermediate category. Hence, there exists polar opposites
which are not vague, e.g. both poles of the abstract/concrete duality. Now a
second difference (ii) between polar opposites and vague objects is that the
former are simple qualities, while the latter consist of either simple or
composite qualities. For there exists so-called multi-dimensional vague
concepts, such as vehicle, machine.[4]
Lastly, a third difference (iii) resides in the fact that some polar opposites
are inherently precise. To take an obvious example, the positive/negative
duality is made up of precise constituents.
Let us also
distinguish, second, polar contraries from the pair consisting of a given
concept and its complement. To take an example, positive/negative are polar
opposites, while positive/non-positive are not. For non-positive includes both neutral
and negative. Respectively,
negative/non-negative are not genuine polar opposites, since non-negative includes both neutral and positive. However, if a given duality A/Ā is exhaustive, it
follows that the polar opposite of A (respectively Ā) identifies itself
with non-A (respectively non-Ā). But as we have seen, not all polar
dualities are exhaustive and this entails that the polar opposite of a given
concept must be distinguished, from a general viewpoint, from its complement.
On the other
hand, it is also worth defining the well-balanced
property. For a given object o of
which one part has a property A, the well-balanced property relative to the
A/Ā duality results from the fact that there also exists another part of o which has the opposite property
Ā. To give an example, protons have a positive charge, while on the other
hand, electrons have a negative charge. Thus, an atom of hydrogen, which
includes one electron and one proton, is well-balanced from the viewpoint of
the positive/negative duality, since it has both a positive and a negative
charge. More generally, being well-balanced relative to our universe results
from a generalisation of this latter property to all polar dualities.
At this step, we
are in a position to state the present argument more explicitly:
|
(1) |
our universe is well-balanced |
premise |
|
(2) |
in our universe the following polar dualities are instantiated:
large/small, positive/negative, external/internal, absolute/relative,
bright/dark, static/dynamic, attractive/repulsive, visible/invisible,
cold/hot, and so on. |
evidence |
|
(3) |
the well-balanced property relative to the A/Ā duality results
from the fact, for a given object having a polar property A, of also having
the opposite property Ā |
definition |
|
(4) |
\the
well-balance of our universe results from the fact that all instantiable
polar opposites are instantiated |
from (1),(2),(3) |
|
(5) |
concrete pertains to
the abstract/concrete duality |
definition |
|
(6) |
concrete objects exists in our universe |
evidence |
|
(7) |
the concrete pole of the abstract/concrete duality is instantiated |
from (6) |
|
(8) |
the abstract pole of the abstract/concrete duality is necessarily
instantiated |
from (3),(4),(7) |
|
(9) |
\ abstract
objects exists in our universe |
from (8) |
At this step, it
is worth highlighting some distinctive features of the present argument. It
should be pointed out first that the argument is deductive. In effect, it
starts from the consideration that our universe is well-balanced and derives
the conclusion that abstract objects do exist. The well-balanced property is
crucial to the argument and two different types of well-balanced properties can
be distinguished: (i) well-balanced relative to a given polar duality A/Ā;
(ii) well-balanced relative to our universe.
It is also useful
to define accurately the scope of the argument. More generally, the argument
postulates that for each pole observed in our universe, there exists an
opposite pole. The argument is thus based on the fact that for every object
that exists and exemplifies a pole,
there also exist in our universe other objects that instantiate the opposite
pole. The argument postulates that there do not exist things in our universe
that instantiate a pole of a given duality without also instantiating the
opposite pole.
Lastly, it should
be pointed out that the above argument can be stated alternatively under the
form of an inductive argument. It could then be recast as follows:
|
(1i) |
in our universe the following polar dualities are instantiated:
large/small, positive/negative, external/internal, absolute/relative,
bright/dark, static/dynamic, attractive/repulsive, visible/invisible,
cold/hot, and so on. |
evidence |
|
(2i) |
the well-balanced property relative to the A/Ā duality results
from the fact, for a given object having a polar property A, of also having
the opposite property Ā |
definition |
|
(3i) |
\in our universe
all instantiable polar dualities are instantiated |
from (1i), induction |
|
(4i) |
the well-balance of our universe results from the fact that that all
instantiable polar opposites are instantiated |
from (1i),(2i),(3i) |
|
(5i) |
concrete pertains to the
abstract/concrete duality |
definition |
|
(6i) |
concrete objects exists in our universe |
evidence |
|
(7i) |
the concrete pole of the abstract/concrete duality is instantiated |
from (6i) |
|
(8i) |
the abstract pole of the abstract/concrete duality is necessarily
instantiated |
from (2i),(4i),(7i) |
|
(9i) |
\ abstract
objects exists in our universe |
from (3i),(4i),(5i) |
It should be noticed that
the inductive form of the argument proceeds by enumerating all instantiable
polar dualities and then generalising to all polar dualities. It follows then
straightforwardly by induction that the abstract/concrete duality is also
instantiated.
3. Response to objections
At this stage, it is worth
considering a set of objections that can be pressed against the present
argument. Let us review, first, a line of objection that stems from the issue
of whether Ryle's argument is a sound one. Grayling (1995, p. 50) mentions in
effect that a sceptic critic could object to Ryle's polar concept argument that
a same line of reasoning applied to other dualities such as
'perfect/imperfect', 'mortal/immortal', 'finite/infinite' would entail the
existence of perfect, immortal or infinite entities. An objection along the
same lines could then be raised against the present argument for abstracta.
However, in the present context, the above three dualities do not deserve the
same type of response. For that reason, I shall consider them in turn. Let us
begin with the perfect/imperfect duality. From the above, it should be apparent
that the perfect/imperfect duality does not fall under the scope of the present
argument. For perfect is not a simple quality. In effect, perfect can be defined
as the sum of all simple positive qualities. Thus, perfect can be characterised
as a complex or composite quality. But as we have seen, the scope of the
present argument is restricted to simple qualities. For that reason, the
existence of perfect entities is not entailed by the current argument.
Let us turn now
to the mortal/immortal duality. At this step, it should be pointed out that it
is not clear whether mortal can be considered as a simple quality, in the sense
defined above. For that reason, I shall replace it by the temporal/atemporal
duality. This latter pair is made up of two conceptual polarities that can be
regarded unambiguously as simple qualities. Now it should be acknowledged that
the temporal/atemporal duality also falls under the scope of the above
argument. And a same line of reasoning yields the existence of atemporal
entities. I shall endorse such a consequence here. In effect, the present
argument is also for the existence of atemporal entities. But is there
something counter-intuitive here? It seems that some objects such as numbers
are obvious candidates for this definition. In effect natural numbers can be
considered consistently as both abstract and atemporal entities.
Now the same goes
for the application of the present argument to the infinite/finite duality. For
it should be acknowledged that infinite and finite are simple qualities in the
sense defined above. Thus the argument also applies to these latter concepts
and yields the existence of infinite objects. But such inference should not be
very disturbing, I think, for it is much in line with our current intuitions.
Just as in the previous case of the temporal/atemporal duality, there exist
natural candidates for the definition of infinite entities. Natural numbers,
for example, straightforwardly instantiate the property of being both abstract
and infinite.
Let us consider,
second, another line of objection. For it could be opposed to the present
argument that a similar line of reasoning postulates the existence of impossible objects. Few would doubt, in
effect, that we currently have a large body of evidence in favour of the
existence of possible objects. Our
universe contains many instances of possible objects. Hence, according to the
above argument, from the possible/impossible duality, we can infer the
existence of impossible objects. But as this latter notion is
self-contradictory, the objection goes, the whole enterprise is vowed to
inconsistency. However, this line of objection does not undermine the force of
the argument, I think. For the present argument is only concerned with
instantiable objects. It begins with the observation that many objects
exemplifying both poles of a given duality do exist. It pursues by inferring
the existence of objects that instantiate a pole of the abstract/concrete
duality. But in all cases, the present argument is only concerned with pairs of
polar contraries that are compatible with existence. Perhaps, some would agree
that certain objects possess the property of being impossible, contradictory or
imaginary. But such inferences do not fall under the scope of the present
argument. For the dualities that are concerned with the present argument need
at least to be instantiable. As a
consequence, predicates such as impossible,
inexistent, imaginary, contradictory,
inconceivable, and so on, should be
discarded from the beginning. And all non-instantiable dualities (i.e.
dualities which contain at least one non-instantiable pole) such as
possible/impossible, existent/inexistent, coherent/incoherent, and so on, are
not concerned with the current argument. In addition, the same response
prevails for a similar line of objection that would respectively infer the
existence of inexistent, inconceivable, imaginary objects, from the existent/inexistent, conceivable/inconceivable,
real/imaginary dualities.
Let us examine,
third, a different line of objection. It runs as follows. The present argument
rests on the necessity of instantiating both poles of all dualities, the
objection goes. But it could be retorted that certain poles of some dualities
need not being instantiated. And such is the case, the objection runs, for the
abstract pole of the abstract/concrete duality. It should be apparent that this
latter objection challenges premise (4), according to which, due to the
well-balance requirement of our universe, all instantiable polar dualities are
exemplified. But this latter objection is not very promising, I think. For the
present polar concept argument is concerned with our universe's well-balanced
requirement. And this well-balance results precisely from the instantiation of
both poles of each duality. Consider the case of the bright/dark duality.
Imagine our universe containing only dark objects, with all bright objects
missing. Would we expect to find ourselves in such an universe? No. For the
emergence of carbon-based life would be impossible in such one-sided (from the
viewpoint of the dark/bright duality) universe. Or consider alternatively the
situation if all objects in our universe were static and no objects were
dynamic. Or else imagine if our present universe only contained cold objects,
and were entirely devoid of hot ones. All such universes would be very
unfriendly, to say the least. Now the same goes for the abstract pole of the
abstract/concrete duality. Perhaps it could be helpful to recall, at this step,
one major premise of the fine-tuning argument. This latter argument derives
from the fact that many cosmological constants are fine-tuned for the emergence
of carbon-based life, the conclusion that this latter feature of our universe
is non-random and due to the intention of its Creator. Now setting aside the
controversial conclusion of the fine-tuning argument, it appears that the
premise according to which the cosmological constants are fine-tuned for
further emergence of carbon-based life can be replaced by the two following
steps:
|
(1f) |
the cosmological constants of our universe
are fine-tuned for the emergence of carbon-based life |
|
|
(2f) |
\ the cosmological constants of our universe are fine-tuned for the
instantiation of the following dualities: large/small, positive/negative,
external/internal, bright/dark, static/dynamic, visible/invisible, cold/hot,
and so on. |
from (1f) |
At this point, it is worth
noting that the assertion according to which our universe is well-balanced is
even weaker than the uncontroversial premise (1f) of the fine-tuning argument.
For consider the following instance of anthropic coincidence related to the gravitational force constant which is
part of (1f):[5]
|
(3f) |
if the gravitational force constant had
been larger then stars would be have been too hot to allow for carbon-based life chemistry[6] |
|
(4f) |
if the gravitational force constant had
been smaller then stars would have been be too cool to permit carbon-based life chemistry |
Now it appears that these
two propositions can be recast as follows:
|
(5f) |
if the gravitational force constant had been
larger then the cold pole of the
cold/hot duality would have not been instantiated |
|
(6f) |
if the gravitational force constant had
been smaller then the hot pole of
the cold/hot duality would have not been instantiated |
To take another example:
|
(7f) |
if the velocity of light had been faster
then stars would have been be too luminous for life support |
|
(8f) |
if the velocity of light had been slower
then stars would have been insufficiently luminous for life support |
can be restated into the
weaker:
|
(9f) |
if the velocity of light had been faster
then the dark pole of the
bright/dark duality would have not been exemplified |
|
(10f) |
if the velocity of light had been slower
then the bright pole of the
bright/dark duality would have not been exemplified |
More generally, every
anthropic coincidence can be restated into the weaker couple of propositions:
|
(11f) |
if the <cosmological constant> had
been larger then the A pole of the A/Ā duality would have not been
instantiated |
|
(12f) |
if the <cosmological constant> had
been smaller then the Ā pole of the A/Ā duality would have not been
instantiated |
At this step, it should be
apparent that challenging (2f) also implies being committed to doubt (1f),
while on the other hand it is a widely accepted premise of the fine-tuning
argument.
The above
argument could be attacked, fourth, on the grounds that is not deductive, but
rather inductive. According to this line of objection, the present argument is
a disguised inductive argument. In effect, if the argument were inductive
instead of deductive, it would be probabilistic and as such, its impact would
be weaker than in its original deductive presentation. As mentioned above, it
should be acknowledged that the argument can be presented alternatively as an
inductive argument. The inductive form of the argument begins with an
enumeration of all exemplified polar dualities. From this, it derives a
generalisation to all polar dualities. The conclusion that the
abstract/concrete duality and in particular its abstract pole is also
instantiated ensues. If the above argument is to be considered as essentially
inductive, this has the effect of weakening the argument by making it inductive
rather than deductive. However, the present argument is not intended to count
as a proof yielding absolute certainty. Then choose whatever variation -
deductive or inductive - of the argument you prefer. In either case, the
essence of the argument remains in force.
It would also be
tempting to challenge, fifth, premise (1), namely the fact that our universe is
well-balanced. But such an objection is not very promising, I think. In effect,
our universe is about 14 billion years old. How could our universe have lasted
so long if it hadn't been well-balanced? Considering now its spatial extension,
a question of the same nature arises. For our universe extends billions of
light years in any directions. How could our universe have occupied such huge
spatial region without being well-balanced? And again: How could our universe
contain so much objects such as neutrons, monkeys, stars, galaxies, and so on,
and a total number of atoms amounting to 1080, without being
well-balanced?
Another line of
objection that could be pressed, sixth, against the present argument is that it
is simply a generalisation of Ryle's argument. However, I shall stress that
Ryle's argument is slightly differently motivated. In effect, the key concept
in the current polar concept argument is the well-balanced property. A key
premise is in effect that being well-balanced is a prominent feature of our
universe. And this last premise is reinforced by the additional premise based
on the empirical fact that some properties of our universe currently
instantiate this well-balanced property. Thus, the present argument is not
entirely a priori as could be characterised Ryle's argument. The present
argument incorporates in effect some empirical features of our universe. In
addition, I should stress that Ryle's argument contrasts 'error' and 'getting
it right'. But it should be apparent that 'error' has a pejorative connotation
and 'getting it right' reveals a meliorative nuance. Hence, 'error' is a
negative concept and 'getting it right' is a positive one. By contrast, the
current argument is only concerned with neutral concepts and pairs of neutral
opposites. Consequently, it is worth stressing that the present argument would
be inapplicable to the 'error/getting it right' pair of concepts.
In conclusion, it
is worth stating accurately the scope of the above argument. It is not designed
in effect to serve as a proof of the existence of abstracta. For given our
current high standards, it should be acknowledged that it does not meet our
present criteria of proof. Rather, the present argument aims at reinforcing an
initial credence that abstract objects could exist. The above argument is
simply designed to increase our a priori belief about the existence of
abstracta. As such, it is consistent with the Quine-Putnam indispensability
argument. It is also consistent with recent trends in cosmology and in
particular with the level IV of the kind of multiverse described in Tegmark
(2003). In this context, the purpose of the present argument for abstracta is
to provide some additional grounds in support of the hypothesis that abstract
objects do exist.
References
|
Colyvan,
M. (2001) "Indispensability Arguments in the Philosophy of Mathematics",
The Stanford Encyclopedia of Philosophy
(Fall 2001 Edition), E. Zalta (ed.),
http://plato.stanford.edu/archives/fall2001/entries/mathphil-indis. |
|
Field,
H. (1980) Science Without Numbers: A
Defence of Nominalism, Oxford: Blackwell. |
|
Grayling,
A. C. (1995) "Scepticism", Philosophy
A guide through the subject, Grayling, G. (ed.), Oxford: Oxford
University Press. |
|
Lowe,
E. J. (1995) "The Metaphysics of Abstract Objects", Journal of Philosophy 92, 509-24. |
|
Maddy,
P. (1992) "Indispensability and Practice", Journal of Philosophy, 89-6, 275-289. |
|
Rosen,
G. (2001) "Abstract Objects", The
Stanford Encyclopedia of Philosophy (Fall 2001 Edition), E. Zalta (ed.),
http://plato.stanford.edu/archives/fall2001/entries/abstract-objects. |
|
Ross,
H. (1995) The Creator and the Cosmos,
Colorado: Navpress Colorado Springs. |
|
Ryle,
G. (1960) Dilemmas, Cambridge:
Cambridge University Press. |
|
Soames,
S. (1999) Understanding Truth, New
York, Oxford: Oxford University Press. |
|
Sober,
E. (1993) "Mathematics and Indispensability", Philosophical Review, 102-1, 35-57. |
|
Tegmark,
M. (2003) "Parallel Universes", to appear in Science and Ultimate Reality: From Quantum to Cosmos, J.D.
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[1] E. J. Lowe (1995) distinguishes
three different conceptions of abstract objects. In what follows, my concern
will be with what he terms abstract1 objects, i.e. in opposition to
concrete objects.
[2] For a survey of the indispensability argument, see Colyvan
(2001).
[3] Cf. Ryle (1960, pp. 94-95): "A country which had no coinage would offer no scope to counterfeiters. There would be nothing for them to manufacture or pass counterfeits of. They could, if they wished, manufacture and give away decorated disks of brass or lead, which the public might be pleased to get. But these would not be false coins. There can be false coins only where there are coins made of the proper materials by the proper authorities. In a country where there is a coinage, false coins can be manufactured and passed; and the counterfeiting might be so efficient that an ordinary citizen, unable to tell which were false and which were genuine coins, might become suspicious of the genuineness of any particular coin that he received. But however general his suspicions might be, there remains one proposition which he cannot entertain, the proposition, namely, that it is possible that all coins are counterfeits. For there must be an answer to the question `Counterfeits of what?'".
[4] From Soames (1999, p. 217).
[5] From Ross (1999).
[6] Paraphrasing Ross.