Possibilianism
Hold the whole possibility space open, then use evidence to close parts of it down
- Difficulty
- Moderate
- Time to result
- ~ongoing to results
- Steps
- 5
- Confidence
- 68%
Eagleman's position sits between religious certainty and strict atheism, and it is more active than agnosticism. The starting observation is scale: what science has written down is a tiny fraction of what is out there. He wrote a piece on ten unsolved mysteries of neuroscience in 2004 and they remain unsolved; nobody can explain how physical cells produce the taste of cinnamon or the beauty of a sunset. Given that, declaring the matter settled in either direction overruns the evidence. Possibilianism's mechanism is the scientific temperament applied to open questions: allow every hypothesis onto the table at the start, use evidence to rule specific ones out, and actively hunt for regions of the possibility space nobody has thought of yet. Agnosticism says 'I don't know' and stops. Possibilianism takes a flashlight and goes looking.
Origin
Extracted from Young and Profiting
Core principles
- 01What we have written down in textbooks is a tiny fraction of what is going on.
- 02Certainty in either direction outruns the evidence available.
- 03Agnosticism is passive not-knowing; possibilianism is active exploration.
- 04Everything gets on the table first; evidence decides what leaves.
- 05The method matters more than the current answer, because the answer will move.
How to run it
- 1
Establish the size of the unknown
Before positioning yourself, size what remains unexplained in the domain. Eagleman's ten unsolved mysteries of neuroscience from 2004 are all still unsolved.
Pro tip Write the open questions down. An unlisted unknown quietly becomes a settled one.
- 2
Put every hypothesis on the table
At the outset, nothing is excluded on grounds of taste, tribe or discomfort. The filtering comes later and comes from evidence.
Watch out Admitting a hypothesis is not endorsing it. Conflating the two is what makes people refuse step 2.
- 3
Rule things out with evidence
Apply the scientific method to eliminate specific claims. A 6,000-year-old Earth fails on Japanese pottery from 7,000 years ago and cave paintings from 30,000 years ago.
Pro tip Ruling out is more tractable than proving. Aim your evidence at elimination.
- 4
Open new folds in the possibility space
Use the same tools to surface options nobody had proposed. The space is not a fixed menu; science adds items to it as well as removing them.
Watch out Skipping this step reduces possibilianism to ordinary scepticism.
- 5
Hold survivors with weights, not verdicts
Gather evidence that weighs in favour of some hypotheses and against others, and let those weights stand as your position rather than resolving to a single answer.
Pro tip State your position as a distribution. It survives new evidence instead of being humiliated by it.
Watch out The pull toward one clean answer is the failure mode; intellectual humility is the whole discipline.
In the wild
Eagleman points at consciousness as the case that defeats confident closure in either direction. You assemble physical stuff and somehow it experiences pain, the beauty of a sunset, the taste of cinnamon, the smell of lemon pie. Nobody can build the equivalent from transistors and honestly say it is enjoying anything; a computer running a funny video is presumably just moving zeros and ones around. We are made of cells and yet we feel things, and no one can explain the step. The possibilian response is neither a religious answer nor a declaration that deterministic physics has it covered, but continued structured exploration.
→ A live question stays live, and the method rather than the answer carries the position.
Eagleman presented possibilianism in a TEDx talk and received hundreds of emails immediately afterward from people saying they thought they were possibilians too. It spread into newspaper articles sent to him from India and Uganda, Facebook groups, and eleven years on, sustained activity. His read is that people had no available position between believing what their parents and culture told them, strict atheism, and passive agnosticism.
→ A named third option gave a large latent group a stance they could actually hold.
Common mistakes
Confusing it with agnosticism
Agnosticism is only not-knowing. Possibilianism is going out to explore the possibility space and shine a flashlight around it, which is an activity, not a shrug.
Using open-mindedness to protect ruled-out claims
The method requires actually eliminating things the evidence kills. Keeping a refuted hypothesis alive because 'we can't know anything' inverts the framework.
Swapping religious certainty for scientific certainty
Declaring that it is a cold universe of nothing but deterministic physics is also a claim beyond current evidence. Eagleman's point is that we do not know enough to pretend science has it all figured out.
Is it for you?
Best for
Anyone facing questions where the evidence is genuinely incomplete but the temptation to pick a tribe and stop thinking is strong.
Not ideal for
Questions the evidence has already closed, where reopening them is a stall rather than a search.
From the transcript
“the scientific temperament always allows lots of hypotheses on the table and then we gather evidence to weigh in favor of some of those”
“possibilism is a much more active thing of saying hey we're going to go out and explore the possibility space and shine a flashlight around…”
“we just don't know enough to pretend that science has it all figured out”
From the episode
David Eagleman: The Psychology of Time, How the Brain Shapes Reality & Human Nature
David Eagleman