Critical Rationalism

Healthcare is an
Epistemology Problem

A good explanation is hard to vary while still accounting for what it purports to explain.

David Deutsch, The Beginning of Infinity

The fundamental failure of current health AI is epistemological, not computational. We apply Popperian critical rationalism - conjecture and refutation - to build AI that creates genuine explanations, not probabilistic guesses.

Deep Dive into Docs
The Problem

The Inductive Fallacy in Healthcare AI

Most health AI makes predictions based on patterns. But pattern-matching is not understanding.

Correlation ≠ Causation

Most AI health tools confuse 'A usually follows B' with 'B causes A'

Pattern matching finds correlations, not causes.

The Black Swan Problem

Rare cases don't match common patterns. Medicine is full of rare cases.

Induction fails on edge cases that matter most.

Easy-to-Vary Explanations

Probabilistic outputs are 'mushy' - you can change details without breaking the theory

'You might have A, B, or C' explains nothing.

We don't want an AI that hallucinates; we want an AI that arrives at hard-to-vary explanations.

Epistemological Foundation

Critical Rationalism in Medicine

We do not look for confirmation; we look for good explanations.

1
Generate

Conjecture

Generate bold explanations for the patient's health state

"What biological mechanisms could explain this?"

2
Destroy

Refutation

Systematically attempt to destroy each explanation

"What evidence would kill this theory? Does the data already contain it?"

3
Select

Survivor Selection

Only explanations that withstand rigorous criticism survive

"Theories survive by being hard-to-vary, not by being likely"

If refuted, generate new conjecture
Hard to Vary (HTV) Criteria

What Makes an Explanation 'Good'?

A good explanation is one that is hard to vary while still accounting for the phenomenon it explains.

— David Deutsch, The Beginning of Infinity Building on Popper's falsificationism
01

Interdependence

Change one part, the whole thing collapses

Components are logically connected

02

Specificity

Makes precise, testable predictions

Not vague statements but concrete claims

03

Parsimony

Explains without arbitrary assumptions

No ad-hoc additions to save the theory

04

Falsifiability

There exists a clear data point that would prove it wrong

The theory makes itself vulnerable

See the Difference

Bad Explanation

Easy to Vary

You feel tired because of a virus.

Good Explanation

Hard to Vary

Your fatigue is caused by Epstein-Barr reactivation. The virus infects B cells, triggering a cytokine response. Your elevated liver enzymes (ALT 67) confirm hepatic involvement.

Every recommendation in Regain is scored on these criteria, not probability.

Multi-Agent System

The Debate Architecture

Simulating a World-Class Medical Team via Adversarial Debate

01

The Intake Agent

Build the Problem

Maps the patient's Health State into a structured timeline of unexplained phenomena

02

The Conjecturer

Generate Theories

Bold hypothesis generation: What biological mechanisms could explain this?

Cannot refute - only propose
03

The Critic

Destroy Theories

Systematic refutation: What evidence would kill each theory?

Cannot confirm - only destroy
04

The Synthesizer

Select Survivors

Picks the theory with fewest contradictions

If all refuted → IDK Protocol
If refuted: return to Conjecturer

Technical Implementation

The system implements the Generator-Verifier-Reasoner (ArgMed) pattern within a LangGraph state machine. Theories are validated against medical consistency schemas using formal verification.

In Popper's framework, a theory that survives rigorous attempts at refutation earns provisional acceptance - never certainty, but the highest epistemic status achievable.

Epistemic Humility

The IDK Protocol

When We Say 'I Don't Know'

A critical failure of current AI is hallucination under pressure - generating confident-sounding answers when it doesn't know. We prioritize epistemic humility.

Three Triggers That Activate IDK

1

All Theories Refuted

Every candidate explanation has been falsified by available evidence. No surviving hypothesis remains.

2

Equally Easy-to-Vary

Surviving theories score identically on hard-to-vary criteria. No explanation stands out as more robust.

3

Missing Critical Data

The discriminating data point that would decide between theories is not available in the current dataset.

What Happens Instead of Guessing

OUTPUT

"Current knowledge is insufficient to distinguish between [Theory A] and [Theory B]."

OUTPUT

"The primary bottleneck is the lack of [Specific Data Point]."

OUTPUT

"Action: Safest-case posture until [Metric] is updated."

We do not guess when we don't know.

The Role of Discriminators

When theories tie, we identify the discriminator - the single test that would kill one theory but not the other.

Surviving Theories Discriminator Logic
Overtraining vs. Insulin Resistance Morning Cortisol Overtraining elevated; IR normal

By identifying the discriminator, we guide the next data collection step rather than making unfounded claims.

Future Work

Open Questions

Problems We're Still Working On

1

Knowledge Creation vs. Retrieval

"Is our multi-agent debate genuinely creating new knowledge, or is it sophisticated retrieval dressed up as knowledge-creation?"

An LLM Critic might just be retrieving counterexamples from training data, not generating genuine counter-arguments.

2

Falsifiability with Delayed Ground Truth

"In medicine, ground truth often takes weeks or months."

How do you think about falsifiability in domains where refutation is delayed?

3

Hard-to-Vary vs. Prior Probability

"Is there a coherent way to combine 'hard-to-vary' with 'prior probability'?"

Or are they fundamentally incompatible epistemologies?

4

Scaling Refutation

"Our Critic uses schema-driven refutation. What other refutation mechanisms should we consider?"

Empirical falsification, logical consistency checking, expert panel review, patient outcome feedback loops.

Documentation

Vision & Product Docs

Explore the technical and philosophical foundation of the Popperian Assessment Engine.

We're Hiring

Join Our Team

We're looking for AI researchers with a strong interest in epistemology to develop the Popper-Deutsch assessment agentic system and apply it to healthcare.

Full-time or Research Collaboration
Shape a New Field
Real Healthcare Impact
Anton Kim

Anton Kim

CEO, Regain Inc.