Horizon: a presumption of reliability, and the burden placed on those least able to carry it.
Justification
What makes a belief one a person is entitled to hold, rather than one they merely happen to have.
- Theme
- Knowledge, truth and reason
- Tradition
- Western
- Term fixed
- 1641
In plain terms
Ask why someone believes something and they give a reason. Ask why they believe that, and they give another. The chain has to end somewhere, and there are only three places it can end.
It can stop at something that needs no support - a foundation. It can loop back on itself, so that beliefs hold each other up. Or it can go on forever, which nobody thinks a person can actually do.
Each option costs something. Foundations have to be self-supporting, and the candidates for that have all been attacked. Circles look viciously circular until you notice that a large enough web is not obviously the same thing as begging the question. That trilemma is the whole architecture of the subject, and it has been in the same shape since antiquity.
As a philosopher would put it
Foundationalism holds that some beliefs are basic - self-evident, incorrigible or evident to the senses - and that all others derive support from them. The classical version has been eroded from both directions: Sellars's attack on the given argues that a state can either justify a belief, in which case it is already conceptual and needs justification itself, or be a bare causal input, in which case it justifies nothing.
Coherentism replaces the pyramid with a web, where a belief is justified by its fit with the rest. The standing objection is that coherence is compatible with being systematically wrong, and that nothing in the system connects it to the world.
The internalist-externalist split cuts across this. Internalism requires the justifying factors to be accessible to the believer. Externalism - reliabilism especially - requires only that the belief be produced by a process that reliably yields truths, whether or not the believer can say so. The clash is sharpest over cases like a reliable clairvoyant with no evidence of their own reliability, who counts as justified on one account and not on the other.
Where you meet it
Between 1999 and 2015 the Post Office prosecuted more than seven hundred sub-postmasters for theft and false accounting. The evidence was the Horizon accounting system, which showed shortfalls in their branches.
Under the law of England and Wales at the time, computer evidence was presumed reliable unless the defence could show otherwise - a presumption introduced in 1999 on the reasoning that requiring proof of correctness for every machine would be unworkable. Sub-postmasters had no access to the system's error logs, no way to examine its code, and no knowledge of other branches reporting the same thing.
Horizon contained thousands of defects. The Court of Appeal quashed thirty-nine convictions in 2021 and described the prosecutions as an affront to the conscience of the court. What failed was a rule about justification: the presumption made a belief entitled by default, and placed the burden of undermining it on the people least able to carry it.
What is actually disputed
Whether justification must be accessible to the believer.
Internalists argue that a person who cannot say why they believe something is in no position to be credited with holding it responsibly, and that externalism severs justification from anything the believer does. Externalists reply that this makes ordinary perceptual knowledge impossible, since almost nobody can articulate why their eyes are reliable, and that what matters is whether the belief was formed well, not whether the believer has a theory of it.
The regress problem underneath remains open. Infinitism - that the chain really is endless and that justification is a matter of having reasons available rather than having traversed them - is a minority position that has never been refuted so much as found implausible, which is not the same thing.
Commonly confused with
- Truth c. 330 BC A belief can be thoroughly justified and false, and true with no justification at all. Keeping the two apart is the first move in epistemology.
- Explanation 1948 Explaining why someone holds a belief - upbringing, incentive - says nothing about whether they are entitled to it.
Defined against
- Doubt Justification is what doubt attacks and what answers it, and the Pyrrhonists built an entire method on the relation
Philosophers
- René Descartes The search for foundations that need no further support
- John Locke Proportioning belief to the evidence
- David Hume The problem of justifying induction, which no foundation reaches
- Karl Raimund Popper Justification abandoned in favour of falsification
- Willard Van Orman Quine The web of belief, with no privileged edge
Works
- Meditations on First Philosophy The foundationalist programme
- An Essay Concerning Human Understanding Proportioning assent to evidence
- A Treatise of Human Nature Where the foundations fail to support induction
- The Logic of Scientific Discovery The proposal to do without justification
- Outlines of Pyrrhonism The regress, set out two thousand years earlier
Schools
- Cartesianism Foundations, and the demand for certainty
- British Empiricism Experience as the base
- Pyrrhonian skepticism Where the regress is used against every position
- Vienna Circle Verification as the criterion of entitlement
- Classical Pragmatism Where the demand is reframed around enquiry
Related concepts
Knowledge c. 369 BC · Belief c. 380 BC · Testimony 1764 · Fallibility 1878 · Coherence 1807
The demand that beliefs be grounded is ancient; Descartes makes the structure of grounding the central question, and the foundations-versus-coherence dispute has run on his terms ever since.