The problem of universals

(Part one of “Scientific Idealism” as a philosophy for system theorists)

Copyright 2016 Graham Berrisford. One of about 300 papers at Last updated 21/05/2017 22:39


A universal is a quality or type such as “tall”, “yellow”, “circular” or “dangerous”.

Universals are properties (attributes and relationships) attributable to particular situations, entities or events.

The “problem of universals” is the question of whether properties exist (or even what it means to “exist”).

While philosophers agree that human beings talk and think about properties, they disagree on whether these universals exist in reality or merely in thought and speech (and records of those).

This paper proposes the philosophy that best fits general system theory might reasonably be called either “Scientific Realism” or “Scientific Idealism”.


Description and reality. 1

The problem of universals. 3

Realism: a property exists independently of any mind or description.. 4

Nominalism: a property exists only when a thing has that property. 5

Idealism: a property is constructed in the mind, so exists only in descriptions of things  5

Conclusions wrt system theory. 8


Footnote 1: A human and social development perspective. 9

Footnote 2: FAQs about Scientific Idealism... 10

Footnote 3: Challenges to Scientific Idealism... 11


Description and reality

Philosophers have long debated the nature of description and reality.

“The distinction has a curious status in contemporary philosophy.

It is agreed the distinction is of fundamental importance.

Yet there is no standard account of how it should be drawn.


One debate might be posed as a question: "Do realities exist outside and independently of minds?"

Another debate, called the "problem of universals", might be posed as: "Do descriptive qualities or properties exist outside and independently of minds and realities?"


At first sight, the two questions require binary yes/no answers, so asking both questions yields four possible combinations of answers.

However, the assignment of philosophers to the four cells of the grid below is not straightforward.


Do realities exist outside and independently of minds?



Do descriptive properties exist

independently of minds and realities?


Platonic Realism?

Metaphysical Idealism (e.g. Berkeley)?


Aristotlean Realism?



There are several difficulties in completing the grid.

First, what a philosopher believes, how they describe their beliefs, and how they are interpreted are not always the same.

Second, the questions refer not only to descriptions and realities, but also to minds and existence.

And the meaning of all four terms is debatable.


·        Do realities include the contents of minds - thoughts, speech and documentation of them?

·        Is a mind the brain of a human? What about the brain of a honey bee, the biochemistry of a sunflower following the sun, or a computer?

·        Does existence imply a material or physical form, locatable in time and space? If not, what does it mean?

·        Are descriptive properties universal property types/variables (e.g. height) or particular property instances/values (e.g. 2 metres tall)?


Regarding universals, Wikipedia says this:

“There are many philosophical positions regarding universals.

Taking "beauty" as example, three positions are:

Platonic realism: beauty is a property that exists in an ideal form independently of any mind or description.

Aristotelian realism: beauty is a property that exists only when beautiful things exist.

Idealism: beauty is a property constructed in the mind, so exists only in descriptions of things.”


(You might perhaps express realism as realities have descriptions, which describers can discover.

And idealism as the view that describers create descriptions to help them deal with realities.)


A reader has written: “If you are an Idealist, then there is no independent ‘state of affairs’ that makes your ideas or assertions ‘true’. So you must live in a post-truth world.”

However, modern idealists don't deny the existence of a mind-independent reality.

Rather, they say we cannot know that reality directly; we can only know what appears true when realities are tested against descriptions.

The question today is not about whether realities exist independently of descriptions; it is about how accurately descriptions model those realities.


As a previous paper explained, knowledge is fuzzy, there are degrees of truth.

You can truthfully point to a particular circus ring and describe it as “circular”.

But on close inspection, no circus ring is perfectly circular.

It is only near enough circular to be usefully described thus to a circus designer or observer..

A truth triangle

True-enough propositions

<create and use>    <describe and predict>

Rational actors  <observe and envisage>   Realities


So, idealists don’t live in a post-truth world; they live in a world where true is true enough to be useful when reacting to and predicting realities.

And usefulness is measured by success in passing whatever tests or experiments we choose to test realities against descriptions.


Today, realism and idealism have evolved into a confusingly diverse and overlapping mess of different positions.

In the end, it is hard to distinguish what this paper calls Scientific Idealism from what others call Scientific Realism.

The problem of universals

Particulars are realities: they are things that exist and may be described.

Such as individual trains, rose bushes, planets and circus rings.


Universals are descriptions: they are concepts, qualities or types that describe particular things.

Such as “dangerous”, “thorny”, “good”, “beautiful”, “circular” or “tasty”.


Most particular chocolate bars are describable, classifiable or typifiable as “tasty”.

You can readily remove a particular chocolate bar from the universe by eating it.

You cannot so readily remove the general type called “tasty”, which might be considered a universal and eternal quality.


So, do universal types exist independently of particulars?

This table is an attempt to classify a variety of views.


View holder?

Types exist eternally, before and after Things that instantiate them.


Types are created when Things instantiate them.


Things can exist before Minds create Types to describe them.


Types can be created in the Mind before Things instantiate them.


Things exist only when described/typified by a Mind.



Note the three key elements in these views are:

·        Things (particular realties)

·        Types (universal descriptions) and

·        Minds (intelligences).


The main question here is: Do Types exist independently of all Things and Minds?

Traditionally, answers are labelled Realism, Nominalism and Idealism.

Realism: a property exists independently of any mind or description

The definitions shaded grey below are taken from Wikipedia’s page on the Problem of Universals (May 2107).


“The realist school claims that universals are real—they exist and are distinct from the particulars that instantiate them.

Platonic realism is the view that universals are real entities and they exist independent of particulars.

Aristotelian realism is the view that universals are real entities, but their existence is dependent on the particulars that exemplify them.”


The position here?

A property (say, “musicianship”) exists independently of any particular individual that property may be attributed to.

If all musicians in the world died, then concept of musicianship would still exist in thought, speech and documentation.

On the other hand, before there was a mind to produce thought, speech or documentation; the concept of musicianship could not exist.


Roger Penrose contends that the philosophy of mathematics can't be understood other than by taking the Platonic realist view.

"mathematical truth is absolute, external and eternal, and not based on man-made criteria ... mathematical objects have a timeless existence of their own..."

However, this contention depends how the term "existence" is interpreted.

A realist may say that mathematical objects exist eternally in an ethereal or logical sense.

An idealist may argue that the term “existence” implies instantiation in a material or physical sense.

In the latter sense, mathematical types and instances have existed (in minds and their products) only since they were conceived by life forms who use them to understand and predict realities.


In the ordinary world we live in, a position known as Scientific Realism is currently favoured by many.

See for example: “Scientific Realism: How Science Tracks Truth” Psillos S. London: Routledge, 1999.

Another source defines Scientific Realism thus:

Scientific Realism

The world has a definite and mind-independent structure.

Scientific theories are true or not because of the way the world is

Our best scientific theories are approximately true of the world.


However, in the world of quantum mechanics, even the values given to property types (such as “position” and “speed”) are seen as creations of observers.

“If you accept quantum physics at face value then at least one of two dearly held principles from the classical world must give.

One is realism, the idea that every object has properties that exist without you measuring them.

For most quantum physicists, it’s realism that has to give.” Anil Ananthaswamy “New Scientist” 13 December 2014

Nominalism: a property exists only when a thing has that property

Nominalists assert that only individuals or particulars exist and deny that universals are real (exist as entities or beings).

The nominalist philosopher agrees that we predicate the same property of multiple entities but argues that the entities only share a name, not a real quality, in common.”


The position here?

You would be foolish to act as though standing on a railway track shares only a name with other “dangerous” situations.

What matters is that it shares a real quality, which just happens to be encoded as “dangerous” in the English language.

We must translate mental models into a shared language to discuss them, but the concept of danger is not inherently linguistic.

Rather, the names we give to properties are merely labels we use to communicate about the underlying concepts or ideas.

Idealism: a property is constructed in the mind, so exists only in descriptions of things

Again, Idealists asserts that “beauty is a property constructed in the mind, so exists only in descriptions of things."


“Idealists, such as Kant and Hegel, posit that universals are not real, but are ideas in the mind of rational beings.

Idealists do not reject universals as arbitrary names; rather, they treat universals as fundamental categories of pure reason (or as secondary concepts derived from those fundamental categories).

Universals, in idealism, are intrinsically tied to the rationality of the subject making the judgment.


“For instance, when someone judges that two cup holders are both circular they are not noticing a mind-independent thing ("circularity") that is in both objects.

Nor are they simply applying a name ("circular") to both.

Rather, they partially constitute the very concept of cup holder by supplying it with the concept of circularity, which already exists as an idea in their rational mind.”

Thus, for idealists, the problem of universals is only tangentially a metaphysical problem; it is more of a problem of psychology and epistemology.”


This grid divides both realism and idealism into two schools.


Descriptions exist without minds


Descriptions are created by minds

Realities exist only as examples

of descriptions

Platonic Realism

Types exist as eternal forms

Metaphysical Idealism (e.g. Berkeley)

Mentality is reality, or the foundation of all reality.

Things exist only when observed

Realities exists independently

of minds and descriptions

Aristotlean Realism

Types exist only in things

Epistemological Idealism (e.g. Kant)

Types exist only in minds and their products


Kant's presumption that knowledge can only be gained through experience implies a very peculiar interpretation of "knowledge" and "experience".

More generally speaking:

·        knowledge of (e.g.) arithmetic and geography is gained through communication during formal education

·        knowledge of how much fuel a rocket needs to reach the moon is gained by the application of logical rules, and

·        the knowledge that jumping off a cliff is dangerous is acquired by inheritance.

Moreover, these three kinds of knowledge are empirically verifiable.


The position here?

Reality is out there, but we cannot understand reality directly, exactly as it is.

We create and use concepts (like “circle”) as a means to understand and deal with particulars.

Descriptive concepts are called universals because they are so widely recognised and useful as models of reality.

Epistemological idealism


<create and use>               <idealise>

Rational beings  <observe and envisage>  Particulars


We generalise this as a position called Scientific Idealism (which is difficult to distinguish from Scientific Idealism).

Scientific Idealism


<create and use>               <idealise>

Life forms     <observe and envisage>    Realities


Our position is that animals have evolved to remember and share descriptions of realities.

We create and use descriptions (mental, linguistic and other models) as a means to understand and deal with particular realities.

Our models need only be accurate enough to predict real world behaviour in a way that helps us.


Scientific Idealism

The structure of the world is composed of separable particulars/things.

Universals/types are constructs of the mind that rational actors use to classify and describe particulars/things.

Universals/types are tools for understanding and dealing with the particulars they describe.


Scientific Idealism sees universals as types or descriptions that are conceived by rational actors.

Universals certainly do exist, but only in mental, documented and other kinds of model.


For example, scientists describe photons (and other elementary quantic entities) in terms of particles and/or waves.

Neither of the universals "particle" or "wave" can fully describe the behavior of light.

Waves and particles are only mental models that are useful (accurate enough) in different contexts.

So, the Scientific Idealist view of light can be represented in a triangle.

Wave-particle duality

Wave and Particle Descriptions

<create and use>                 <idealise>

Scientists           <observe and envisage>               Light

Conclusions wrt system theory

This table offers answers to six questions related to the problem of universals.

Some philosophical questions

Scientific Idealist answers

Do realities exist that have never been described?

Yes. The existence of mind-independent things is not disputed (above the level of quantum mechanics).

Do descriptions exist that have never been realised?

Yes. We can envisage a “flying horse” though no things of that type exist in reality.

Do minds exist outside and independent of reality?

No. They are biological things; they are part and parcel of the real world.

Do minds exist without and independent of descriptions?

No. Mindfulness implies the ability to observe, envisage and describe realities.

Do descriptions exist that have never been conceived in a mind?

No. Descriptions exist in minds and the products of minds (see discussion below).


Again, it is hard to distinguish the answers of a Scientific Idealist from those of a Scientific Realist.

See Footnote 3 for further discussion of this.



“Planet” is a type; particular cosmic bodies are things that instantiate that type.

A Scientific Idealist view of the solar system can be represented in a triangle.

The “Planet” type

<create and use>           <idealises>

Astronomers <observe and envisage> Particular cosmic bodies


Note that cosmic bodies cannot be described as instantiating the type “planet” until that type is described.

Also, other types (“spherical”, “solid”, “gas giant”, “earth-like”) might be abstracted from observation of cosmic bodies.

And types (like “cuboid planet”) can be purely imaginary – never realised in a particular thing.



More generally, Universals are types; particulars are things that instantiate types.

A Scientific Idealist view of universals can be represented in the same triangle.


<create and use>             <idealise>

Rational actors       <observe and envisage>           Particulars


Note again that things cannot be described as instantiating a type until that type is described.

Also, infinite types might be abstracted from things we observe or envisage.

And types (like “flying unicorn”) can be purely imaginary – never realised in a particular thing.



Abstract system descriptions are types; concrete systems are things that instantiate system descriptions

The Scientific Idealist view of systems can be represented in the same triangle.

Abstract system descriptions

<create and use>             <idealise>

System describers <observe and envisage> Concrete systems


Note that a discrete real-world entity (e.g. a named business or machine) cannot rightly be called a system until that system is described.

Also, infinite systems might be abstracted from any business or machine we observe or envisage.

And envisaged business systems (“target systems”) can be purely imaginary – never realised in a particular business


Footnote 1: A human and social development perspective

As children we may be nominalists to a degree.

We learn type names by pointing to a thing and asking: What’s that thing?

Somebody tells us that thing is a “rose bush”, and so shares their type name with us.

That doesn’t mean we understand the general type, and the two of us may go on to use the term differently.


Later, we learn a type elaboration that defines the type named rose bush

E.g. the elaboration associates the concept called “rose bush” with concepts called “flowering”, “thorny” and “bushy”.

This, our mental models embed one concept in a network of inter-related concepts (much as in a dictionary).


Is every type indisputably defined?

No. There might no a universal agreement about exactly what a rose bush is.

The definition of the concept or type we label “rose bush” is a kind of jury decision.


Is every thing indisputably of a type or not?

No. The conformance of any particular plant to the general rose bush type may be loose or fuzzy..


What about mathematical types – such as numbers and circles?

Hmm… Numbers and circles are rigorously defined using the rules of logic, with respect to axioms

These types now exist in countless mental and documented models.

The type definitions include operation types that can be performed on numbers and circles.

All over the world, people use these universal operations to perform calculations on particular numbers and circles

Which is to say, number and circle types are excellent tools for modelling reality.


Such mathematical types are so widely shared, so successful, you might believe them to be mind-independent.

But Scientific Idealism takes the view that they are mind-dependent.

However many times the type called “circle” is conceived, it remains a product of intelligence.


It seems reasonable to call numbers and circles universals, because they are so widely shared and so successfully used.

But it also seems self-aggrandising to believe that our mental models are so important they exist outside of minds and the products of minds.

Surely, the concept of number or circle did not exist before life? And has there ever been a perfect circle?

Footnote 2: FAQs about Scientific Idealism

The realities of interest are those which can be observed or envisaged and described.

The questions for us are not so much whether types and properties (dangerous, thorny, good, beautiful, circular, customer and address) exist.

The questions are rather these.


Q) Do universal types (e.g. “circle, “planet”or “customer”) exist without actors to create and use them?

No. With no actors there is no abstraction and no mind-independent idea.

Has there ever been a perfect circle in the real world?

The things now called planets existed in the universe life, but there was no concept of a planet.


Q) Does everything exist without being described?

No. Natural things do exist before they are described.

But designed things (symphonies, chairs and software programs) only exist in the world after they have been described

They are the products of minds in which some kind of description was formed before the thing was made.


Q) Can we reason about concepts/properties/types using only their names?

No. You cannot reason knowing only a type name (like number, circle, rose bush or planet).

You can only reason when you know the properties of that type – to be found in some kind of type elaboration.

Given a small and simple concept (like number or circle), you can readily hold it properties in mind and reason about it.

Given a large and complex concept (like a business system), it is so difficult to remember its properties and reason about it that a written description becomes essential.


Q) Do concepts in exist in a collective consciousness?

No. A mathematician has written that: "Numbers do not have a tangible existence in the world.”

But numbers do exist in perceptible (if intangible) forms, in mental images and in documents.

He further wrote:  “They exist in our collective consciousness.”

Few of us would independently reinvent the concept of number – defined by the operations that can be performed on them.

Since there is no collective consciousness, we go to school to learn the concept of number.


Q) Are simple universal types different from more complex parochial types?

There seems to be a spectrum from the former to the latter.

Concept category




Simple, logical

Hard science

“Number” and “Circle”

appear widely understood and not open to interpretation or judgement.


Everyday experience

“Beauty” and “Danger”

more open interpretation or judgement.

Complex, parochial

Law and business

“Homicide” and “Bank account”

understood only in a “bounded context” or “domain of knowledge”.


Note however that one type of number is defined differently in the Java and C++ programming languages.

Footnote 3: Challenges to Scientific Idealism

You might argue Scientific Idealism would be better labelled Scientific Realism.

What follows is a response to that argument.


Are universals mind-independent to the extent that they exist eternally?

If realism means proposing that a universal quality or concept is eternal, that is to postulate something outside of time and space.

There is no fossil, geological or cosmological evidence of concepts before life.

The existence of a concept before cannot be proved or falsified.

It seems a pointless proposition, a fancy, a useless idea, and Occam’s razor can be used to remove it.


It is more pragmatic to propose every universal concept has a life history.

To begin with there was no thinker and no thought; no conceiver and no concept.

Then thinkers evolved.

A concept is born whenever a thinker conceives a concept (be it “circle” or “flying unicorn”)

A concept is encoded in at least one mental, documented or other kind of model.

A concept may be shared and copied any number of times.

If and when all copies are destroyed, then the concept disappears from the current state of the universe.


If it were possible to live in a world without types, we could still name individual things, situations, entities and events.

But we could not describe things as instances of types.

Because a thing cannot be called an instance until there is a type to which it conforms


It seems egoistic or anthropocentric to believe that human knowledge is so fundamental to the world it must have existed before human life.

Scientific Idealists posit knowledge did not exist before life, though we can describe things that existed before life, and will exist after it.


To be sure, the things we typify as rose bushes and planets do exist in reality.

But the concept or type labelled “rose bush” or “planet” did not exist before life.

What about apparently eternal types such as “number” and “circle”?

If it were possible to destroy all minds and products of minds (including all computers).

Then all universal concept, types and descriptions (even “circle”) would disappear from the universe.


Doesn’t realism (rather than idealism) presume there is a mind-independent reality?

Scientific Idealism takes it as axiomatic that a mind-independent reality existed before there were minds.

The question is not about the nature of reality; it is about the nature of description.

Scientific Idealism is about the process of creating a description by idealisation - by classification or typification.

(This appears to be the defining characteristic of intelligence, both natural and artificial.)

And about the process of realising a description in a testable reality.


Wikipedia contrasts classical Realism and Idealism thus.

"Platonic realism: beauty is a property that exists in an ideal form independently of any mind or description.

Idealism: beauty is a property constructed in the mind, so exists only in descriptions of things."


Doesn’t idealism (rather than realism) presume there is no mind-independent reality?

There is no suggestion here that Scientific Idealism exactly matches the Idealism of Kant or Hegel.

However, Kant did contrast the phenomenal world, in which we live, and the noumenal world.

“The noumenal world exists only as a heuristic for our cognitive capacities.”


Science describes realities; conversely, realities that cannot be described can play no part in science.

The world is deeply mysterious, far beyond our direct understanding.

However, descriptions of that world (mental, document and other) are vital to our survival.

So, our knowledge of the world must be accurate enough to help us deal with it.


Scientific Idealism does not presume to draw the same description-reality distinction Kant did.

But it does distinguish descriptions from the realities they describe.

Science describes realities; conversely, realities that cannot be described can play no part in science.


The true nature of light is not directly accessible to us.

Light is modelled as either waves or particles in scientific descriptions.

But scientists don't actually believe light is either waves or particles in reality; those are only accurate enough descriptions.


A description is idealised from reality by one or more rational actors; it could not exist before life.

It exists in the sense it is held or encoded in at least one mental, documented or other model (which is itself part of reality).

Descriptions of the world can be accurate, inaccurate or somewhere in between.

We need descriptions that are accurate enough to be useful, to help us thrive and survive.

By "enough" I mean only - the description/model/proposition works - it passes those empirical tests we choose to judge its truth by


Is idealism incompatible with testing the accuracy or precision of models?

Scientific Idealism doesn't question whether reality exists independently of description.

It questions only whether universals (and descriptions of any kind) are mind-independent and real in the sense that they are eternal - so exist outside of space and time.

"The realist school claims that universals are real—they exist and are distinct from the particulars that instantiate them."

“Realists tend to argue that universals must be posited as distinct entities in order to account for various phenomena.”

“... in denying that the eternal Forms are mental artifacts [this] differs sharply with modern forms of idealism.”

"Idealists, such as Kant and Hegel, posit that universals are not real, but are ideas in the mind of rational beings."


There is no external mind-independent standard against which to judge “accurate enough”.

How do we test the truth of descriptions based on universals like “circular” or Newton’s laws of motions?

We measure the values of qualities of realities (like Diameter, Force = Mass * Acceleration).


“As Einstein would have happily admitted [his] new physics was not a definitive answer, nor did it negate the importance of Newton’s contribution.

It was not “right” or “true”, but simply a more accurate explanation that Newton’s”, which was perfectly good for its time.

As a pragmatist would say, it was a valid explanation” Marcus Weeks

Newton's laws are accurate enough to pass such tests in the world we live in.


How do we test the truth "universals" like "beauty" and "good" when applies to a perceptible situation, entity or event?

We may measure them by asking people’s opinions in a survey of some kind.

Another way is to form a hypothesis that predicts the outcome of an entity being described as "beautiful" or "good".

The practical difficulty of the experiment, along with disinterest in trying, doesn't mean that testing is impossible.



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