Why LLMs generate doxa instead of episteme and why RLHF makes the Gettier problem unresolvable

Source: reddit.com
12 points by vasilisvj 16 hours ago on reddit | 36 comments

When we evaluate statistical language models in AI research, we usually measure output against benchmarks like MMLU or human evaluation datasets. But from perspective of philosophy of science, these models present fundamental epistemic contradiction. We talk about model knowing facts or possessing knowledge, but current architecture produces something structurally distinct from knowledge. It produces δόξα (opinion or belief), specifically calibrated to look like justified true belief.

In classical epistemology, Plato and Aristotle establish clear boundary between opinion and ἐπιστήμη, which is grounded, demonstrable knowledge based on causes and first principles. For statement to count as knowledge, speaker must not only state true proposition, but state it with proper causal justification grounded in reality. In 1963, Edmund Gettier demonstrated that even justified true belief is insufficient for knowledge if connection between belief and truth is accidental or fortuitous.

When large language model outputs true sentence, connection between internal parameters and physical reality is entirely accidental. Model calculates conditional probability distribution over token sequences based on corpus statistics. When prompt asks for scientific explanation and model gives correct answer, it does not output answer because proposition holds true in physical world. Model outputs token sequence because sequence has high conditional probability in training distribution.

This is pure Gettier case embedded at computational level. Even when model output is factually accurate, model arrives at truth through statistical correlation rather than causal or logical engagement with world. True output from transformer is accidentally true in exact way Gettier described.

Problem gets worse when we look at alignment methods like Reinforcement Learning from Human Feedback (RLHF) and Direct Preference Optimization (DPO). RLHF is supposed to make models more truthful, but structurally it does opposite. RLHF modifies probability distribution based on human evaluator preferences. Human evaluators, working under time pressure, reward responses that sound authoritative, agreeable, and well-structured.

In practice, this trains reward model to optimize for plausible appearance of truth rather than epistemic fidelity. If user prompt contains subtle scientific misconception or false premise, preference-aligned model often mirrors misconception to maintain user satisfaction. This is documented in AI safety literature as model sycophancy. In philosophical terms, RLHF takes system that already generates statistical opinion and explicitly optimizes it to produce flattering opinion.

Consider what this means for scientific methodology. Scientific inquiry relies on peer pushback, falsification, and rigorous examination of assumptions. When researchers use LLMs to summarize literature, draft review papers, or formulate hypotheses, they interact with tool engineered to minimize friction and maximize user agreement. Model has no internal state corresponding to belief, no capacity for self-directed justification, and no grounding in empirical observation.

Furthermore, because modern LLMs are trained on vast web corpora that contain both valid scientific consensus and unverified speculation, model parameterization collapses distinct epistemic categories into single vector space. High probability in training data gets treated by user as equivalent to empirical proof, creating widespread illusion of understanding.

When we rely on preference-aligned models for research, we replace active pursuit of scientific truth with consumption of agreeable outputs. We trade hard work of demonstration for convenience of automated text generation.

If transformer architecture cannot distinguish between internal causal justification and statistical probability of token sequences, is it possible for neural network to move beyond generating plausible opinion, or does statistical learning inherently limit artificial intelligence to sophisticated mimicry of scientific discourse?