Graph Neural Networks: A Technology Between Continuous Approximation and Semantic Discontinuity — Can AI Get Closer to Meaning?

AI approximates the world remarkably well.

With astonishing precision,
smoothly and seamlessly,
it captures the structure of reality.

And yet, from time to time,
we feel a strong sense of discomfort.

“What it says is correct.
But it does not understand the meaning.”

The source of this discomfort is not a lack of performance.

It is something more fundamental.

It is the difference between

what can be approximated
and what cannot be approximated in principle.


What AI Does: Continuous Approximation

Let us begin with the facts.

At the core of modern AI are:

  • distribution estimation

  • function approximation

  • gradient-based updates

In other words, AI performs

approximation of a continuous world.

If something is similar, it is close.
If it changes slightly, the output changes slightly.

0.49
0.50
0.51

These differences are handled

smoothly.

This property is exactly why AI can behave so naturally.


The World Appears Continuous

The physical world
and much of our data

appear continuous at first glance.

Temperature
Speed
Revenue
Probability

Because of this, we tend to assume:

“Meaning must also be something that can be approximated continuously.”

But here lies a critical misunderstanding.


Meaning Emerges from Discontinuity

Meaning does not exist within continuity.

Meaning appears at the moment of

a cut.

For example:

0.49
0.51

At some point this difference becomes

Pass / Fail
Allowed / Denied
Safe / Dangerous
Legal / Illegal

Here we observe a

jump.

This jump exists

outside continuous approximation.


The Better the Approximation, the More Meaning Disappears

A paradox appears here.

The more smoothly AI approximates,

the more

boundaries blur
taboos fade
contextual tension disappears.

As a result,

the points of discontinuity where meaning arises

are filled in and smoothed away.

This is why we sometimes feel:

“It is correct, but it is wrong.”


Meaning Is Where We Draw the Line

Structurally speaking,

meaning can be described as:

  • what is included

  • what is excluded

  • where the boundary is drawn

This is

a decision.

And decisions cannot be directly derived from

  • probabilities

  • gradients

  • optimization.


Where Does Meaning Remain?

Meaning does not fully reside

inside the model.

Nor is it completely contained in the data.

So where does it exist?

Meaning remains at

points of logical discontinuity.

For example:

  • Do not apply in this condition

  • Stop the decision process in this case

  • Return this case to human judgment

In other words, meaning appears as

  • boundaries

  • stop conditions

  • exception handling

This is where meaning resides.


Graph Neural Networks (GNN)

If we summarize the discussion so far,

AI technologies can be divided into two worlds.

The World of Continuous Approximation

  • LLM

  • CNN

  • Transformer

These operate in

vector space.

The World of Meaning

Here we see:

  • Ontology

  • Semantic Web

  • Rules

  • DSL

These are

logical structures.

Thus the AI landscape contains two layers:

  • the continuous world

  • the world of meaning.

At this point, an interesting technology appears.

That technology is

Graph Neural Networks (GNN).


GNN Learns Structure

GNNs are somewhat unique.

Most AI models operate on

vectors.

But GNNs operate on

graphs.

A graph consists of:

  • nodes (entities)

  • edges (relationships)

For example:

Product
├ Category
├ Reviews
└ Purchase history

Patient
├ Symptoms
├ Tests
└ Diagnosis

Design proposal
├ Options
├ Concerns
├ Rejected reasons
└ Stop conditions

All of these represent

relational structures.

GNNs learn by propagating information through these relationships.


GNN Moves Closer to Meaning

This is an important point.

Meaning often emerges from

relationships.

For example,

the reason a design proposal was rejected may depend on:

  • component constraints

  • safety standards

  • past accidents

  • cost

These decisions exist within a

network of relationships.

In other words,

much of meaning exists as

graph structures.

GNNs can learn these structures.

For this reason,

GNNs can be considered

the machine learning method closest to meaning.


But Even GNN Cannot Fully Handle Meaning

However, an important clarification must be made.

GNNs do not understand meaning.

What GNNs learn are

statistics of relationships.

For example,

they can learn that a structure like

A → B → C

frequently appears.

But deciding

“stop here”

is not a statistical pattern.

It is a

designed rule.

In other words,

GNNs can

approximate meaning structures,

but they cannot determine

where meaning should be cut.


The Three-Layer Structure of AI

We can summarize the discussion as a three-layer structure.

Continuous approximation
(LLM / Deep Learning) ↓ Relational structure
(GNN) ↓ Semantic discontinuity
(Ontology / Rules / Boundary)

In other words:

AI approximates the world.

GNN learns relationships.

Design defines the discontinuities.


What Is Design?

This brings us back to the initial question.

If AI cannot handle meaning,

who writes meaning?

The answer is:

design.

Design is the act of understanding the limits of AI

and defining in advance

the points of discontinuity

where meaning emerges.

For example:

  • Do not make decisions below this probability

  • Do not automate this type of case

  • Return this case to human judgment

These

boundaries

are where meaning resides.


Conclusion

AI can approximate the world continuously.

GNN can learn relational structures.

But meaning emerges from

discontinuity.

And that discontinuity

does not arise inside the model.

It exists as

designed boundaries.

AI reflects the world.

GNN learns relationships.

But the thing that creates meaning

is the human who decides

where to cut.

The real question in the age of AI is not:

“Can we build AI that understands meaning?”

The real question is:

Who is writing the discontinuities where meaning emerges — and where are they written?


Technical details related to GNN can be found in the article Graph Neural Networks.”
For AI technologies that handle meaning structures, readers may also refer to Semantic Web technologies and Ontology engineering. Those interested are encouraged to consult those resources as well.

タイトルとURLをコピーしました