Noam Chomsky: Language, Cognition, and Deep Learning | Lex Fridman Podcast #53

Core Cognitive and Linguistic Principles

• Chomsky argues that while human intelligence is complex, it possesses inherent biological limits defined by genetic endowment, similar to how DNA prevents humans from developing insect visual systems or wings.
• The "mechanical philosophy" prevalent from Galileo to Newton, which required understanding the world via machine-like contact interactions, was abandoned by scientists like Newton when faced with non-mechanical forces (e.g., gravity), leaving humans with a cognitive inability to fully comprehend such mysteries.
• Human cognition instinctively imposes structures like perfect geometric figures or invisible mechanical links on observations (e.g., infants perceiving distorted triangles as perfect or inventing invisible forces between moving objects), indicating built-in limits to how the world is interpreted.
• Noam Chomsky rejects the belief that human intelligence can answer any question in principle, asserting that as biological organisms, our cognitive scope is bounded by our specific organic nature.

Internal vs. External Language Systems

• Language consists of two distinct concepts: an internal system localized in the brain that determines infinite expressions, and an external system consisting of the physical noises expressed into the atmosphere.
• Most human language use is internal thought, with externalization being a secondary function of the internal cognitive faculty.
• The internal language faculty is a unique genetic endowment with no remote equivalent in any other organism, serving as the core mode for constructing and expressing human thought.
• Chomsky identifies "structure dependence" as the most profound property of language, noting that humans process structural relationships rather than linear proximity, even when linear cues are the only sensory data available.
  • Example: In the phrase "Carefully, the guy who fixed the car is tall," listeners interpret "carefully" as modifying "is tall" based on structural hierarchy, ignoring the linearly closer verb "fixed."
  • This cognitive process requires carrying out complex structural computations on material that is never explicitly heard in that form.

Machine Learning, Deep Learning, and AI

• Chomsky classifies deep learning and neural networks primarily as engineering tools for pattern recognition rather than scientific inquiries into the nature of language or cognition.
• Current deep learning models operate by finding patterns in massive datasets without conducting "critical experiments" that test theoretical boundaries, a methodology Chomsky contrasts with standard scientific practice.
• He argues that deep learning fails as a science because it performs well even on systems that violate linguistic rules (e.g., using linear proximity instead of structure dependence), proving it does not discover the actual nature of human language.
• Chomsky posits that adding machines to the human brain (e.g., via Neuralink) may expand cognitive capacity in terms of information bandwidth but cannot fundamentally alter native cognitive limits or allow humans to "understand" unintelligible systems like quantum mechanics in a way that resolves their paradoxes.
• The idea that deep learning vindicates Skinnerian behaviorism is rejected; while it mimics behavioral patterns, it does not address the innate, generative structures of the human mind.

Philosophy, Institutions, and Human Nature

• Chomsky contends that societal "evil" and specific institutions (like market systems) are products of historical contingency and power dynamics rather than essential, unchangeable aspects of human nature.
• Human nature is capable of accommodating vastly different social structures, including systems rooted in a potential innate instinct for freedom from illegitimate domination.
• The meaning of human existence is not an inherent universal truth but is generated by individual activities and actions.
• Chomsky notes that while he pondered the implications of his own consciousness ceasing to exist at age twelve, the scientific community offers no definitive answer to whether the universe depends on an observer's consciousness.

Historical Context and Intellectual Legacy

• Chomsky compares the birth of modern linguistics in the 1950s to Galileo's challenges to obvious physical assumptions, where the prevailing view that languages could differ arbitrarily was replaced by the discovery of universal constraints on language.
• He views the realization that the internal language system is distinct from the external object as a transparent observation that required the intellectual courage to question "common sense" rather than a complex discovery.
• Chomsky identifies the observation of structure dependence as a pivotal moment of excitement in his career, leading to the explanation of how human language operates beyond linear processing.