Can AI Rely on the Systematicity of Truth? The Challenge of Modelling Normative Domains

A key assumption fuelling optimism about the progress of Large Language Models (LLMs) in accurately and comprehensively modelling the world is that the truth is <i>systematic</i>: true statements about the world form a whole that is not just <i>consistent</i>, in that it contains no contradictions, but <i>coherent</i>, in that the truths are inferentially interlinked. This holds out the prospect that LLMs might in principle rely on that systematicity to fill in gaps and correct inaccuracies in the training data: consistency and coherence promise to facilitate progress towards <i>comprehensiveness</i> in an LLM's representation of the world. However, philosophers have identified compelling reasons to doubt that the truth is systematic across all domains of thought, arguing that in normative domains, in particular, the truth is largely asystematic. I argue that insofar as the truth in normative domains is asystematic, this renders it correspondingly harder for LLMs to make progress, because they cannot then leverage the systematicity of truth. And the less LLMs can rely on the systematicity of truth, the less we can rely on them to do our practical deliberation for us, because the very asystematicity of normative domains requires human agency to play a greater role in practical thought.