Argument from Position to Know: "I Was There — I Saw It"
"I grew up there — I know what that neighbourhood is like." "I was in the room when the decision was made." "I have lived with this condition for twenty years; don't tell me what it feels like." Each of these claims carries a distinctive kind of authority: the authority of firsthand experience. It is one of the most natural and powerful forms of evidence available to us. It is also one of the most frequently misused.
The Structure of the Argument
The argument from position to know is a formal argumentation scheme identified by philosopher Douglas Walton. In its basic structure, it runs as follows:
- Position premise: Source A is in a position to know whether proposition P is true or false.
- Assertion premise: A asserts that P is true (or false).
- Conclusion: P is (presumptively) true (or false).
Notice the word presumptively. Walton's framework treats this as a defeasible inference — one that holds unless rebutted, not one that is logically guaranteed. The argument from position to know does not give us certainty; it gives us a reasonable starting point, a presumption in favour of the claim that can be challenged and revised.
This makes it subtly different from the argument from expert opinion, with which it is often confused. Expert opinion invokes formal credentialing, training, or peer recognition within a field. Position to know invokes a more immediate, situational epistemic advantage: being present, being embedded, having direct access to the relevant information. A witness to an accident is in a position to know what happened, without necessarily being an expert in accident reconstruction.
When the Argument Is Legitimate
There are many contexts where positional knowledge is genuinely authoritative and should be taken seriously.
Testimonial evidence. Legal systems rest heavily on the argument from position to know. An eyewitness to a crime, a patient describing their own symptoms, a worker reporting conditions in their factory — all of these are treated as credible starting points precisely because these individuals were there and others were not. The law recognises that not all testimony is equal: a witness who was two feet away is in a better epistemic position than one who was a block away.
Local knowledge. A resident who has lived in a neighbourhood for thirty years has genuine knowledge about it that a visiting researcher lacks. A farmer who has worked the same land for decades understands its micro-patterns in ways that satellites and sensors don't capture. The Nobel Prize-winning economist Friedrich Hayek built much of his critique of central planning on exactly this point: local, dispersed knowledge cannot be replicated by centralised institutions, no matter how well-resourced.
Lived experience. In health advocacy, disability rights, and social justice discourse, personal testimony about what it is like to live with a condition, identity, or social position carries genuine evidential weight. When people with chronic illness report that certain treatments are ineffective, or when members of a marginalised community describe experiences of discrimination, dismissing these reports as "merely anecdotal" is often a form of epistemic arrogance — a refusal to acknowledge that firsthand experience provides access to knowledge that outsiders lack.
The Critical Questions
Walton's scheme comes paired with a set of critical questions — the tests that must be applied to determine whether a particular instance of the argument is sound:
- Is the source genuinely in a position to know? Being at a scene is not the same as being in a position to understand what you observed. A bystander who saw a car accident from fifty metres away in poor lighting is in a weaker epistemic position than one who was standing on the kerb.
- Is A honest? Even someone perfectly positioned to know may have reasons to misrepresent what they know — self-interest, loyalty, embarrassment, or deliberate deception.
- Is the assertion consistent with other evidence? If a witness's account contradicts physical evidence, CCTV footage, or multiple other witnesses, positional advantage alone does not carry the day.
- Is the domain one in which positional knowledge is reliable? Some kinds of experience give access to objective facts; others generate subjective interpretations. The distinction matters.
Where It Goes Wrong
The argument from position to know becomes fallacious — or at least, epistemically unreliable — in several recognisable ways.
The fallibility of eyewitness testimony. Decades of psychological research have established that eyewitness memory is far less reliable than courts and common sense have assumed. Studies by Elizabeth Loftus and others have shown that memories are reconstructive, not reproductive: they are built each time they are recalled, influenced by subsequent information, leading questions, stress, and the expectations of the rememberer. The certainty with which a witness says "I saw it clearly" is often inversely correlated with their actual accuracy. Being present is necessary but not sufficient for reliable knowledge.
Expertise confusion. Positional knowledge does not confer general expertise. A patient's lived experience with a disease is real and important, but it does not make them an authority on treatment protocols across populations. A soldier who served in a war can speak to their own experience; they cannot necessarily speak for the experience of all soldiers, or assess the strategic dimensions of the conflict. Conflating personal position with broader authority is a common and consequential error.
The "I was there" trump card. In online debate, "I was there" is often deployed not as evidence to be weighed but as a conversation-ending trump card. The implication is that anyone who wasn't physically present has nothing valid to contribute. This can be a form of epistemological gatekeeping — using the argument from position to know to shut down inquiry rather than advance it. Compare ad hominem attacks that attempt to discredit opponents rather than engage their arguments: "I was there" can function as a reverse ad hominem, immunising one's own testimony from scrutiny.
Motivated perception. What we observe is always filtered through what we expect, want, and fear. Confirmation bias affects not just what we remember but what we notice in the first place. Two people present at the same event may come away with radically different accounts — not because one is lying, but because they were attending to different things, processed them through different frameworks, and reconstructed different memories afterward. See also: confirmation bias.
The Epistemology of Presence
There is a deeper philosophical question lurking behind all of this: what, exactly, does presence give you access to?
Being at the site of an event gives you access to raw sensory data — what you saw, heard, smelled, felt. But facts are not raw data. The same scene can be described in incompatible ways depending on the conceptual framework applied to it. A police officer and a protester present at the same demonstration may give equally sincere, equally detailed, and mutually incompatible accounts of what happened — not because either is lying, but because they were categorising and interpreting the same sensory stream through different conceptual lenses.
This does not mean that firsthand testimony is worthless. It means that we should treat it as strong but fallible evidence — exactly the kind of defeasible presumption that Walton's framework describes. Presence provides a genuine epistemic advantage that should not be dismissed. But it does not provide infallibility, and the person in possession of it should be the last to claim that it does.
Practical Implications
When evaluating an argument from position to know, the productive approach is neither to dismiss it reflexively nor to accept it uncritically. Ask: what specifically does this person's position give them access to? What does it not give them access to? Is their claim one that positional knowledge can reliably settle, or does it reach beyond what experience alone can establish? Are there other witnesses, and do their accounts converge?
The goal is to weight testimonial evidence appropriately — taking it seriously as a data point while subjecting it to the same critical scrutiny we apply to all evidence. The argument from position to know is a powerful starting point. It is not a finishing line.
Sources & Further Reading
- Walton, Douglas N. Argumentation Schemes for Presumptive Reasoning. Lawrence Erlbaum, 1996.
- Walton, Douglas, Chris Reed, and Fabrizio Macagno. Argumentation Schemes. Cambridge University Press, 2008.
- Loftus, Elizabeth F. "Eyewitness Testimony." Scientific American, 1979.
- Hayek, Friedrich. "The Use of Knowledge in Society." American Economic Review 35(4), 1945.
- Wikipedia: Argumentation scheme