Gettier case

A Gettier-case marker — the subject has a justified true belief that falls short of knowledge because the justification is defective or accidentally related to the truth. A solver-set flag only; never reasoner-promoted.

Structure

Types: gmeow:JustificationStatus

Practical Pattern

Use gmeow:justificationStatusGettier as a controlled value typed as gmeow:JustificationStatus.

Example Snippets

These snippets are generated from canonical slice examples and trimmed to the Turtle blocks where this term appears.

Justification And Defeat

@prefix gmeow: <https://blackcatinformatics.ca/gmeow/> .
@prefix ex:    <https://blackcatinformatics.ca/gmeow/examples/epistemics/> .
@prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd:   <http://www.w3.org/2001/XMLSchema#> .



# SPDX-FileCopyrightText: 2026 Blackcat Informatics® Inc. <paudley@blackcatinformatics.ca>
# SPDX-License-Identifier: CC-BY-4.0
#
# Worked example — epistemic justification and defeat (, Principle 8).
#
# Three cases:
#   1. Justified belief: Ada believes it is noon because a working wall clock
#      reads 12:00. The DoxasticState is justifiedBy the EvidenceSpan of the
#      clock reading, and the DoxasticStandpointClaim reports that held state.
#   2. Gettier-defeated belief: Ada believes it is noon because a stopped clock
#      happens to show 12:00. The evidence is the same kind (a clock-face
#      reading), but a solver flags the state defeatedBy
#      gmeow:justificationStatusGettier because the justification is misleading —
#      the belief is true only by accident.
#   3. Lie: Bob privately believes it is noon (held DoxasticState/Claim), but
#      publicly projects that it is 3pm (projected DoxasticStandpointClaim). The
#      lie is a gmeow:Event of eventTypeLie linking the held and projected
#      standpoints; the divergence IS the deception.

# --- Case 2: Gettier-defeated belief (stopped clock) -------------------------
# Same evidential kind as Case 1, but the basis is misleading: the clock is
# stopped and only happens to show the correct time. The solver marks the state
# as a Gettier case; the reasoner never infers this.
ex:adaGettierBelief a gmeow:DoxasticState ;
    rdfs:label "Ada's Gettier-defeated belief that it is noon"@en ;
    gmeow:epistemicAgent ex:ada ;
    gmeow:doxasticContent ex:timeNoon ;
    gmeow:credence "0.95"^^xsd:decimal ;
    gmeow:doxasticClaim ex:adaGettierClaim ;
    gmeow:justifiedBy ex:stoppedClockReading ;
    gmeow:defeatedBy gmeow:justificationStatusGettier .

Common Companion Terms

gmeow:JustificationStatus