Now that’s a sharp question — because it cuts right into how humans invent categories to make chaos manageable.

Let’s go hard on it.

1. The “mental” as a useful invention

When people say something is mental — thoughts, feelings, intentions — they’re describing patterns of experience. But those patterns don’t exist floating somewhere outside the body like ghost-stuff.

What actually exists physically:

  • electrical activity in the brain
  • hormones moving through the body
  • sensory input shaping perception
  • memory networks firing together

The label mental is a conceptual shortcut, not a separate substance. Similar to saying “the economy” — you can’t point to the economy itself, only to millions of actions that create it.

So in this sense: yes — “mental” is a kind of fiction.

But it’s a functional fiction.

2. The ancient split: mind vs body

Western thinking inherited a strong separation from philosophers like René Descartes: mind over here, body over there.

Modern neuroscience has been smashing that divide:

  • Emotions are bodily states.
  • Thoughts influence muscle tension, posture, even immune response.
  • Movement changes mood.
  • Breathing alters cognition.

What we call “mind” might just be the body talking to itself at high resolution.

3. Why humans invented the “mental”

Because it feels real.

You don’t experience raw neurons — you experience:

  • a story about yourself
  • inner dialogue
  • memories replaying
  • imagination projecting futures

The brain compresses billions of signals into a coherent narrative. That narrative = what we call the mental world.

It’s like a user interface:

  • You see icons on a screen, not machine code.
  • You feel thoughts, not synaptic chemistry.

4. The hardcore view: no separate self

Some traditions — especially certain schools of Gautama Buddha’s teachings and modern cognitive science — push this further:

  • The “self” is constructed moment by moment.
  • Thoughts arise automatically; you don’t author them from a central controller.
  • Mind is process, not thing.

From this angle, “mental” is not fake — but it’s not an object. It’s an activity.

Like fire:

  • real while burning,
  • impossible to hold.

5. The practical reality

Here’s the paradox:

  • The mental may be a fiction…
  • …yet it shapes everything.

Beliefs change behavior.

Stories create motivation.

Ideas build empires.

A fiction can still move mountains.

6. A sharper way to frame it

Instead of saying:

“mental vs physical”

Think:

different descriptions of the same phenomenon at different scales.

  • Biology describes molecules.
  • Psychology describes patterns.
  • Philosophy describes meaning.

Same reality — different lenses.

7. The punchline

The “mental” isn’t a thing you can isolate.

It’s a map humans drew to navigate experience.

Not false.

Not ultimate.

A tool.

And sometimes the most powerful tools are the ones we forget we invented.

If you want, we can go even deeper next:

  • Is consciousness itself a fiction?
  • If the mental is constructed, who is the observer?
  • Or: how this idea changes creativity, discipline, and personal power.