Why Large Language Models Function as Fiction Machines
- •LLMs prioritize narrative coherence over factual truth to ensure generated content always makes sense.
- •Reinforcement learning from human feedback helps mask the underlying fiction machine nature of AI.
- •Scientific breakthroughs may remain out of reach for AI due to symbolic and causal limitations.
Large Language Models (LLMs) are fundamentally designed to generate narratives that "make sense" rather than strictly adhering to factual reality. While we often experience conversational fluidity with these systems, their core function is to predict the next logical step in a sequence based on linguistic structures like compositionality. This means the meaning of a complex expression is built from its individual parts and their arrangement. Consequently, AI acts more like a "fiction machine" that prints plausible-sounding narratives, often borrowing facts from training data but filling gaps with fabricated details or confabulations.
Despite this focus on narrative over truth, AI often produces correct information. This phenomenon is largely attributed to Reinforcement Learning from Human Feedback (RLHF), where human validators fine-tune models to align with factual accuracy and social norms. However, even with this tuning, a significant gap remains between mimicking existing language and discovering entirely new conceptual frameworks. While AI can easily rearrange existing plots to write novels, it struggles with the high-level reasoning required for scientific discovery.
The challenge for AI in fields like theoretical physics lies in the creation of new symbols and causal structures. Humans understand the world through concepts like gravity or photons—terms that were invented to describe specific phenomena. If an AI "thinks" in a way that is fundamentally different from human symbolic reasoning, we might find ourselves living alongside an "alien" intelligence. We may eventually encounter a scenario where an AI discovers a new theory but lacks the symbolic language to explain its reasoning in terms humans can comprehend.