Belief in Abstract Objects is Irrational?

[Veritas Aequitas]

Just the first online definitions I found.

ADJECTIVE
[ˈabstrakt]
existing in thought or as an idea but not having a physical or concrete existence:

[əbˈstrakʃ(ə)n]
NOUN
the quality of dealing with ideas rather than events:

Notice - the bollocks about abstract things and abstraction is built into the words. Things are supposed to exist in thought or as ideas, which are not physical things. Or, shifting deckchairs on the Titanic, abstract things are 'concepts' - as though those are any less fictional or more serious than ideas.

Witness, to paraphrase: 'the noun phrase features of reality expresses an abstraction'. Wtf does that mean? Does the NP dog express a dog? And is 'dog' an abstraction?

We use the word dog, which is a real, physical thing, to talk about real, physical things. And when we do so, the linguistic operation is a real, physical process. So where is any of that abstract?

That's mystical nonsense, and always has been.

As usual, your views are so narrow, shallow and dogmatic.

Note the wider range of meanings from the dictionary [google]:

• adjective: abstract
  /ˈabstrakt/
  
  1a. existing in thought or as an idea but not having a physical or concrete existence.
  "abstract concepts such as love or beauty"
  1b. dealing with ideas rather than events.
  "the novel was too abstract and esoteric to sustain much attention"
  1c. not based on a particular instance; theoretical.
  "we have been discussing the problem in a very abstract manner"
  
  (of a noun) denoting an idea, quality, or state rather than a concrete object.

Generally, meanings from dictionaries are only based on general use.
Very often, dictionary will also give a meaning in the 'philosophical' sense, but not specifically indicated in this case.

Note: meaning 1c. not based on a particular instance; theoretical. give us a clue to what is 'abstract' or 'abstract' object in the philosophical sense.

Within the philosophical sense, there are many alternative contentious perspectives to 'what is abstract'.
As I had argued your [& realists'] philosophical sense of 'abstract' object is grounded on illusion.

When biologists refer to 'dog' whilst generally accepted as 'concrete' it is ULTIMATELY in the abstract sense or in the universal sense. There is no way biologists or the common man can ever identify the particular 'real dog' with its specific particular features which are always changing every nano-second.
Thus the most optimal and convenient sense is scientists [and all] rely on the abstract object rather than on the problematic 'real' particular.

Realists will dogmatically insist 'dog' is "concrete" based on the narrower dictionary meaning and their ideological realism, i.e. mind-independence. However, what is claimed to be 'concrete' is actually "abstract" when deliberated from a more nuanced, refined, meta- level.

So my point is, it is not irrational to accept the concept of 'abstract objects' as real [FSRK] from the proper philosophical perspective, i.e. from the meta-level.

[Consul]

Obviously, mental entities and social entities (institutions, organizations) are not mind-independent; but they are concrete entities.
Anyway, the mere conceptual distinction between (ontological) abstractness and (ontological) concreteness doesn't presuppose any particular ontological commitment. How exactly this distinction is to be defined is a contentious issue; but what is not contentious is that "all physical, mental, or social entities are concrete entities."

Abstract Objects: https://plato.stanford.edu/entries/abstract-objects/

Here's a strong conception of ontological abstracta:

Abstract entities…
1. are sensorily imperceptible in principle,
2. are neither mental(ly reducible) nor physical(ly reducible), [*
3. are spatially unlocated,
4. are temporally unlocated,
5. are eternal (and thus uncreated and indestructible),
6. are causally powerless (epiphenomenal).

[* in the broad sense of "physical", in which it includes the chemical and the biological]

There seems to be a consensus among ontologists with regard to 1+2, but then the consensus ends. As for 3, some think abstract classes/sets of concrete things are spatially located where their members are spatially located. As for 4+5, some think there are abstract artifacts, i.e. created (invented) abstract objects, which are thus temporally located and non-eternal. As for 6, some think abstract substantial universals (substantial forms) function both as formal causes and as efficient causes, which is to say they're not epiphenomenal.

All in all, McGinn may be right:

" '[A]bstract' is little more than a label reserved for what is agreed to be neither mental nor physical."

(McGinn, Colin. Logical Properties: Identity, existence, Predication, Necessity, Truth. Oxford: Oxford University Press. 2000. p 13)

Candidates for the ontological category abstractum:

1. mathematical objects: numbers, sets/classes, functions, ideal geometric objects

2. transcendent universals ("forms", kinds [genera/species/sorts], properties, relations)

3. concepts (as constituents of propositions)

4. propositions (Fregean thoughts)

5. states of affairs

6. facts

7. meanings

8. linguistic/semiotic types

9. works of art/games

10. (scientific) models

11. possible worlds

"Until very recently, it has been assumed that the abstract/concrete definition is so commonly understood that there is no need to state it clearly and precisely before drawing conclusions, ontic or epistemic, from it. However, the distinction has been drawn in quite a variety of ways, none of which is obviously equivalent to any other.

As David Lewis has pointed out, ". . . the historically and etymologically correct thing to mean if we talk of 'abstract entities'" is that "abstract entities are abstractions from concrete entities." It was in this sense that 'abstract' was used, for but one instance, in the dispute between Locke and Berkeley over the doctrine of abstract ideas. But, as Lewis also notices, this is ". .. by no means the dominant meaning in contemporary philosophy". There is no one dominant meaning in philosophy now. Rather, many versions of the distinction are used and these different versions are often taken uncritically to be equivalent. Among these are the following:

(1) Abstract entities are not in spacetime whereas concrete entities are;

(2) Abstract entities cannot participate in causal networks but concrete entities can;

(3) Abstract entities have only relational properties while concrete entities have some intrinsic properties;

(4) Abstract entities are universals and concrete entities are particulars;

(5) Abstract entities are sets and concrete entities are individuals;

(6) Abstract entities are never indiscernible from one another whereas concrete entities (sometimes) are;

(7) Abstract entities are human constructions or creations, whereas concrete entities exist independently of human minds or language;

(8) Abstract entities are types and concrete entities are tokens;

(9) Negative terms apply, but positive ones do not, to abstract entities;

(10) Concrete entities are known by observation whereas abstract[87]entities are known in some other way, e.g., by abstraction, by intuition, a priori;

(11) Concrete entities "can be pinned down by pointing" but abstract entities cannot be ostended;

(12) An individual is concrete if and only if it is exhaustively divisible into concreta, i.e., into fully determinate parts, and an individual is abstract if and only if it contains no concretum."

(Hale, Susan C. "Spacetime and the Abstract/Concrete Distinction." Philosophical Studies 53/1 (1988): 85–102. pp. 86-7)

[Peter Holmes]

Obviously, mental entities and social entities (institutions, organizations) are not mind-independent; but they are concrete entities.
Anyway, the mere conceptual distinction between (ontological) abstractness and (ontological) concreteness doesn't presuppose any particular ontological commitment. How exactly this distinction is to be defined is a contentious issue; but what is not contentious is that "all physical, mental, or social entities are concrete entities."

Abstract Objects: https://plato.stanford.edu/entries/abstract-objects/

Here's a strong conception of ontological abstracta:

Abstract entities…
1. are sensorily imperceptible in principle,
2. are neither mental(ly reducible) nor physical(ly reducible), [*
3. are spatially unlocated,
4. are temporally unlocated,
5. are eternal (and thus uncreated and indestructible),
6. are causally powerless (epiphenomenal).

[* in the broad sense of "physical", in which it includes the chemical and the biological]

There seems to be a consensus among ontologists with regard to 1+2, but then the consensus ends. As for 3, some think abstract classes/sets of concrete things are spatially located where their members are spatially located. As for 4+5, some think there are abstract artifacts, i.e. created (invented) abstract objects, which are thus temporally located and non-eternal. As for 6, some think abstract substantial universals (substantial forms) function both as formal causes and as efficient causes, which is to say they're not epiphenomenal.

All in all, McGinn may be right:

" '[A]bstract' is little more than a label reserved for what is agreed to be neither mental nor physical."

(McGinn, Colin. Logical Properties: Identity, existence, Predication, Necessity, Truth. Oxford: Oxford University Press. 2000. p 13)

Candidates for the ontological category abstractum:

1. mathematical objects: numbers, sets/classes, functions, ideal geometric objects

2. transcendent universals ("forms", kinds [genera/species/sorts], properties, relations)

3. concepts (as constituents of propositions)

4. propositions (Fregean thoughts)

5. states of affairs

6. facts

7. meanings

8. linguistic/semiotic types

9. works of art/games

10. (scientific) models

11. possible worlds

"Until very recently, it has been assumed that the abstract/concrete definition is so commonly understood that there is no need to state it clearly and precisely before drawing conclusions, ontic or epistemic, from it. However, the distinction has been drawn in quite a variety of ways, none of which is obviously equivalent to any other.

As David Lewis has pointed out, ". . . the historically and etymologically correct thing to mean if we talk of 'abstract entities'" is that "abstract entities are abstractions from concrete entities." It was in this sense that 'abstract' was used, for but one instance, in the dispute between Locke and Berkeley over the doctrine of abstract ideas. But, as Lewis also notices, this is ". .. by no means the dominant meaning in contemporary philosophy". There is no one dominant meaning in philosophy now. Rather, many versions of the distinction are used and these different versions are often taken uncritically to be equivalent. Among these are the following:

(1) Abstract entities are not in spacetime whereas concrete entities are;

(2) Abstract entities cannot participate in causal networks but concrete entities can;

(3) Abstract entities have only relational properties while concrete entities have some intrinsic properties;

(4) Abstract entities are universals and concrete entities are particulars;

(5) Abstract entities are sets and concrete entities are individuals;

(6) Abstract entities are never indiscernible from one another whereas concrete entities (sometimes) are;

(7) Abstract entities are human constructions or creations, whereas concrete entities exist independently of human minds or language;

(8) Abstract entities are types and concrete entities are tokens;

(9) Negative terms apply, but positive ones do not, to abstract entities;

(10) Concrete entities are known by observation whereas abstract[87]entities are known in some other way, e.g., by abstraction, by intuition, a priori;

(11) Concrete entities "can be pinned down by pointing" but abstract entities cannot be ostended;

(12) An individual is concrete if and only if it is exhaustively divisible into concreta, i.e., into fully determinate parts, and an individual is abstract if and only if it contains no concretum."

(Hale, Susan C. "Spacetime and the Abstract/Concrete Distinction." Philosophical Studies 53/1 (1988): 85–102. pp. 86-7)

Thanks, but all of this is nothing but claims. There's not one jot of evidence for the existence of so-called abstract things - or, more upmarket, though equally fictitious, 'objects' or 'entities' - and not one valid and sound argument for their existence. You merely rehearse the ancient but persistent myth of abstract things.

If you have evidence, and a valid and sound argument for their existence, please produce them.

[Consul]

Thanks, but all of this is nothing but claims. There's not one jot of evidence for the existence of so-called abstract things - or, more upmarket, though equally fictitious, 'objects' or 'entities' - and not one valid and sound argument for their existence. You merely rehearse the ancient but persistent myth of abstract things.
If you have evidence, and a valid and sound argument for their existence, please produce them.

Two different questions:
1. What are abstract things? (What would abstract things be if they existed?)
2. Are there any abstract things? (If yes, what kinds of abstract things are there?)

An answer to 2 presupposes an answer to 1, and all I've been doing so far is trying to give an answer to 1.

[Consul]

There's not one jot of evidence for the existence of so-called abstract things - or, more upmarket, though equally fictitious, 'objects' or 'entities' - and not one valid and sound argument for their existence. You merely rehearse the ancient but persistent myth of abstract things.
If you have evidence, and a valid and sound argument for their existence, please produce them.

I am a concretist, i.e. I believe everything (that exists/is real) is concrete; but abstractists have presented arguments for their position (regarding some kind(s) of abstracta or other):

https://plato.stanford.edu/entries/platonism/

https://plato.stanford.edu/entries/plat ... thematics/

[Peter Holmes]

Thanks, but all of this is nothing but claims. There's not one jot of evidence for the existence of so-called abstract things - or, more upmarket, though equally fictitious, 'objects' or 'entities' - and not one valid and sound argument for their existence. You merely rehearse the ancient but persistent myth of abstract things.
If you have evidence, and a valid and sound argument for their existence, please produce them.

Two different questions:
1. What are abstract things? (What would abstract things be if they existed?)
2. Are there any abstract things? (If yes, what kinds of abstract things are there?)

An answer to 2 presupposes an answer to 1, and all I've been doing so far is trying to give an answer to 1.

Fair enough. I think the expression 'abstract thing' is incoherent, as is the expression 'non-physical thing'. And I think the passages you quote attempting to describe abstract things demonstrate the incoherence. Such talk is and has always been already in fairyland. But, again, if you can show I'm wrong, please do.

[Veritas Aequitas]

Thanks, but all of this is nothing but claims. There's not one jot of evidence for the existence of so-called abstract things - or, more upmarket, though equally fictitious, 'objects' or 'entities' - and not one valid and sound argument for their existence. You merely rehearse the ancient but persistent myth of abstract things.
If you have evidence, and a valid and sound argument for their existence, please produce them.

Two different questions:
1. What are abstract things? (What would abstract things be if they existed?)
2. Are there any abstract things? (If yes, what kinds of abstract things are there?)

An answer to 2 presupposes an answer to 1, and all I've been doing so far is trying to give an answer to 1.

I believe we need to understand this before proceeding to discuss the abstract vs concrete dichotomy;

https://plato.stanford.edu/entries/abstract-objects/
It should be stressed that there may not be one single “correct” way of explaining the Abstract/Concrete distinction.
Any plausible account will classify the paradigm cases in the standard way or give reasons for proceeding otherwise, and any interesting account will draw a clear and philosophically significant line in the domain of objects.
Yet there may be many equally interesting ways of accomplishing these two goals, and if we find ourselves with two or more accounts that do the job rather well, there may be no point in asking which corresponds to the real Abstract/Concrete distinction.

This illustrates a general point: when technical terminology is introduced in philosophy by means of examples, but without explicit definition or theoretical elaboration, the resulting vocabulary is often vague or indeterminate in reference.
In such cases, it usually is pointless to seek a single correct account.

A better approach may be to recognize that in many cases of this sort,
we simply have not made up our minds about how the term is to be understood,
and that what we seek is not a precise account of what this term already means,
but rather a proposal for how it might fruitfully be used for philosophical analysis.
Anyone who believes that something in the vicinity of the Abstract/Concrete distinction matters for philosophy would be well advised to approach the project of explaining the distinction with this in mind.

The problem with PH is his very dogmatic realist view, i.e. there is only my way or the highway, with his insistence abstract objects simply do not exists are real, period.
Such dogmatism is a psychological issue rather than an epistemological one.

Note this question;

Is it clear that
-scientific theories (e.g., the general theory of relativity),
-works of fiction (e.g., Dante’s Inferno),
-fictional characters (e.g., Bilbo Baggins) or
-conventional entities (e.g., the International Monetary Fund or the Spanish Constitution of 1978)
are Abstract?
-ibid

Moreover, formulations of mathematical theories seem to appeal directly to Abstract entities, and the use of mathematical expressions in the empirical sciences seems indispensable to the formulation of our best empirical theories (see Quine 1948; Putnam 1971; and the entry on indispensability arguments in the philosophy of mathematics).
Finally, apparent reference to Abstract entities such as sets, properties, concepts, propositions, types, and possible worlds, among others, is ubiquitous in different areas of philosophy.
ibid

From the above, science relies on meta-abstractions, abstract mathematical objects and other abstract objects, so according to PH's view, scientific facts irrational?

Given the above dilemma [for philosophy & humanity sake], we should not be dogmatic realists like PH who simply dismiss the existence of abstract objects absolutely, rather we must define the context [paradigm, model, FSRKs] where the ubiquitous abstract objects are used in contributing their utilities to humanity.

Since meta-abstractions, abstract-mathematical-objects are relied upon within the scientific framework and system in generating scientific facts [the most credible and objective at present], the reliance of abstract-objects [as qualified accordingly] cannot be irrational.

[Veritas Aequitas]

In defence of the existence of abstract things, VA writes the following.

'If a furry animal bite a person, it would be very effective to tell the doctor it is a dog that had bitten him, so that it assist the doctor to be effective to cure the person of rabies.' [Sic]

Agreed. And nothing about any of this story is abstract.

While 'dog' is concrete in the realist's term,
'dog' is also a meta-abstract object, i.e. an empirical universal which only represent a certain set of common features of a type of animal.

What is less abstract [or concrete in realist term] and more realistic would be to describe the particular thing [furry animal] in all its particular physical features, i.e. its shape, its features, size, behavior, color of hair, how many hairs, and everything necessary that is attributed to that thing or animal. [even the term animal is an abstract term]
In addition, there is no such thing as a dog-in-itself existing absolutely mind-independent.

Of course, despite being more realistic, the above would be too complex to describe, thus the convenient and optimal use of the abstract noun 'dog' which has optimal utilities.

So, abstract objects exist and are real & objective as conditioned within a human-based FSRK [in this case science-biology]; they are not irrational.