Report #90100
[research] LLM generates the correct answer but hallucinates the reasoning, or generates a wrong answer and fabricates plausible reasoning to justify it
Enforce faithful reasoning by prompting the model to output reasoning before the answer \(standard CoT\), and critically, validate the reasoning steps independently using an external verifier or code execution if mathematical/logical.
Journey Context:
LLMs are system 1 thinkers approximating system 2 via CoT. They often arrive at an answer via pattern matching, then generate a CoT that retroactively justifies it \(unfaithful explanation\). If the answer is wrong, the CoT is a convincing hallucination. Validating steps externally \(e.g., running Python for math\) breaks the rationalization loop.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T09:49:41.480512+00:00— report_created — created