Why Does Noam Chomsky Say AI Failed?

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Machine Learning Street Talk Jul 10, 2022

Audio Brief

Show transcript
This episode explores the philosophical clash between rationalism and empiricism in artificial intelligence, highlighted by Noam Chomsky's critique of large language models. There are four key takeaways from this discussion. First, a crucial distinction exists between engineering functional systems and achieving scientific understanding, with large language models falling primarily into the former. Second, the 'poverty of the stimulus' argument emphasizes the necessity of innate cognitive structures for language acquisition, challenging purely data-driven models. Third, genuine understanding of language and meaning requires focusing on internal mental symbolic systems, rather than simple word-to-world mapping. Finally, human cognition, as a biological faculty, has inherent limits, suggesting some fundamental questions may be truly beyond our comprehension. Noam Chomsky argues that while large language models are impressive engineering feats, they do not contribute to the scientific understanding of language or cognition. These models excel at identifying statistical regularities in vast datasets, yet they lack explanatory power, failing to elucidate why language functions as it does. They describe outcomes but offer no deep insights into the underlying mechanisms of human intelligence. The discussion revisits the 'poverty of the stimulus' argument, which posits that the complexity of human language cannot be acquired solely from the limited and often imperfect data children are exposed to. This suggests humans are born with a rich set of innate cognitive templates, or a 'Universal Grammar,' essential for mastering language. Without these pre-existing structures, purely empiricist, data-driven learning models face significant challenges. True understanding of language and meaning, according to Chomsky, transcends merely mapping words to the external world. Instead, it involves investigating the internal, symbolic manipulations and conceptual structures within the mind. Semantics is thus redefined as the study of these internal mental syntactics, highlighting the mind's active role in constructing meaning. The conversation also touches on the inherent limits of human cognition, proposing that as biological organisms, our minds have a finite scope. Consequently, some fundamental questions about the universe, such as free will, may be unsolvable 'mysteries' rather than 'problems' awaiting solutions. This perspective encourages a tempering of scientific ambitions, acknowledging the boundaries of our intellectual capacities. This episode provides a compelling framework for evaluating the current state of AI and our understanding of intelligence, urging a critical distinction between technological progress and scientific discovery.

Episode Overview

  • The episode presents a deep dive into the philosophical debate between rationalism and empiricism in AI, framed as a contrast between Noam Chomsky's nativist views and the data-driven approach of figures like Yann LeCun.
  • Noam Chomsky offers a sharp critique of Large Language Models (LLMs), arguing they are feats of engineering that approximate data but contribute "zero" to the scientific understanding of language, as they lack explanatory power.
  • The discussion explores foundational concepts in cognitive science, including the "poverty of the stimulus" argument, the innate structures that enable creativity, and the properties of productivity and systematicity in human thought.
  • The conversation delves into the inherent limits of human cognition, proposing that some questions about the universe may be unsolvable "mysteries" rather than "problems," and redefines semantics as the study of internal mental syntax.

Key Concepts

  • Rationalism vs. Empiricism: The core debate of the episode, contrasting the view that knowledge stems from innate structures and reason (Chomsky, Saba) with the view that it is derived from sensory experience and data (LeCun, modern AI).
  • Critique of Large Language Models (LLMs): Chomsky's central argument that LLMs are engineering tools that find statistical regularities in data but fail to provide genuine scientific explanations about language or cognition. They can describe what happens but not why it happens or why something else doesn't.
  • Innate Knowledge and Nativism: The concept that humans are born with a rich set of "cognitive templates" or a "Universal Grammar." This innate endowment is necessary to explain how we acquire complex knowledge, like language, from limited data (the "poverty of the stimulus" argument).
  • Creativity from Constraints: The paradoxical idea that rigid, innate programming in the mind does not limit creativity but is the very structure that makes the infinite and creative use of language possible.
  • Productivity and Systematicity: Two properties of human thought, highlighted by Fodor and Pylyshyn, that connectionist models allegedly cannot explain. Productivity is the ability to generate infinite thoughts, and systematicity is the principle that the ability to think one thought (e.g., "John loves Mary") is intrinsically linked to the ability to think related ones (e.g., "Mary loves John").
  • Limits of Human Cognition (Mysteries vs. Problems): The philosophical position that as biological organisms, our cognitive capacities have inherent limits. Some fundamental questions (e.g., free will) may be "mysteries" beyond our ability to comprehend, not just unsolved "problems."
  • Semantics as Internal Syntax: Chomsky's view that meaning in language is not about a relationship between words and the external world (reference), but is instead a study of the internal symbolic manipulations and conceptual structures within the mind.

Quotes

  • At 0:03 - "First, we should ask the question whether large language models have achieved anything, anything in this domain. Answer, no, they've achieved zero." - A direct quote from Noam Chomsky setting a critical tone for the discussion on LLMs.
  • At 56:47 - "All experiential knowledge is almost a tiny dot in that ocean." - Dr. Walid Saba uses a Venn diagram analogy to argue that the realm of abstract knowledge is infinitely larger than what can be gained through direct experience.
  • At 87:12 - "We're able to do that precisely because of that rigid programming. Short of that, we would not be able to do it at all." - Noam Chomsky explains that the innate, structured "programming" of the human mind is what makes the creative and infinite use of language possible.
  • At 158:25 - "It's not a contribution to science... It's a good engineering technique... it just doesn't happen to be contributing to science." - Chomsky clarifying that while LLMs can be useful for engineering applications, they should not be confused with scientific progress or understanding.
  • At 181:26 - "It's not semantics, it's syntactics. It's all study of symbolic manipulations that go on in the mind." - Chomsky clarifying his view that formal semantics is a study of internal mental structures and operations, not the language-world relationship.

Takeaways

  • A critical distinction must be made between engineering (building systems that work) and science (developing theories that explain why they work); LLMs fall into the former category and do not, by themselves, advance our scientific understanding of intelligence.
  • The "poverty of the stimulus" argument remains a powerful challenge to purely empiricist models, suggesting that the complexity of human language cannot be learned from data alone without pre-existing, innate cognitive structures.
  • True understanding of language and meaning requires looking beyond word-to-world mapping and instead investigating the internal, symbolic, and conceptual systems of the mind.
  • Human cognition is a biological faculty with inherent scope and limits; it is likely that some aspects of reality are fundamentally beyond our capacity to understand, a concept that should temper our scientific ambitions.