Philosophy and Science of Learning

INSTRUCTOR

Daniel Rothschild

ABOUT

The recent advances in AI are powered by learning algorithms that allow computers to develop abilities through training on data. These advances provide an unprecedented opportunity to study learning from a new angle: we now have powerful learning systems whose internals we can inspect, whose training we can control, and whose performance we can measure precisely. This gives us new traction on foundational questions about the nature of learning.

This module uses machine learning as a window into those questions. It covers the foundations of machine learning from a theoretical and conceptual perspective, develops a taxonomy of modern ML paradigms, and asks what the remarkable recent successes of AI tell us about how learning works — in machines and, perhaps, in biological minds.

MECHANICS

Classes will mostly be on Tuesdays from 1-4pm in the seminar room, 19 Gordon Square, 101. We will always have a 20-30 minute break.

Assessment: Essay One (800 words – 30%), Essay Two (2,200 words – 70%)

All unlinked readings available here (ask instructor for password).

All staff and students are welcome at any sessions.

BACKGROUND READING

This class will cover quite a few topics in machine learning and some on human learning. If you want to read or listen to a semi-popular book that covers a lot of recent background, I recommend Tom Griffiths’ new book, Laws of Thought, which will give you useful background on symbolic AI, neural networks, language acquisition, and Bayesianism.

Other useful resources are various online courses on machine learning, such as Andrew Ng’s machine learning course, the classic version of which is on youtube. There are many online courses; the practical programming side will not be useful for this course, but the basic theory will be.

SCHEDULE

28 APRIL: LEARNING AS SEARCH

Learning, across all its forms, can be understood as search through a space of possible systems guided by experience — a framework broad enough to encompass Bayesian updating, standard paradigms of machine learning, and human cognitive development.

Optional: Leibniz, New Essays (selections) (1765); Rothschild, “The Scope of Bayesianism”

5 MAY: LEARNING AS A COMPUTATIONAL PROCESS

This class discusses the relationship between the theory of computation and learning. We discuss the difference between theoretical limits in computation and practical ones. We dive into a bit the difference between discreet and continuous systems, and introduce neural networks as general purpopse systems (capable of contiunous adjustments).

Background: Valiant, Probably Approximately Correct (2013); Valiant, PAC learning paper (1984)

12 MAY: A TAXONOMY OF MACHINE LEARNING

I introduce a unifying engine behind the apparent diversity of modern AI successes — language models, image generation, game play: supervised learning. In the process this session develops a taxonomy of machine learning paradigms.

Optional: Smolensky, “On the Proper Treatment of Connectionism” (1986)

19 MAY: REINFORCEMENT LEARNING AND MOTIVATION

Reinforcement learning is introduced technically — temporal difference learning, value functions, Deep Q-learning — before the session pivots to ask what the reward signal actually is for human learners, whether understanding itself can be intrinsically rewarding, and what kind of values are coherent enough to specify an objective function at all.

2 JUNE: LLMS: ASSOCIATIONISM AND FAST INFERENCE

The taxonomy from previous sessions might suggest that the dominant learning mechanism in modern AI is essentially associationist — gradual, error-driven, domain-general — and this session asks how slow associationist training produces systems capable of fast, flexible, apparently reasoning-like behavior at inference time, with language emerging as the key to the answer.

4 JUNE 1-3pm: STUDENT PRESENTATIONS

9 JUNE: LANGUAGE AND LEARNING

Only AI systems trained extensively on natural language exhibit powerful domain-general reasoning, and this session argues that the explanation lies in language’s properties as a compression system — making general inference computationally tractable — with implications for the longstanding debate about the role of language in human thought.

Supplementary: Fedorenko et al., “Language is Primarily a Tool for Communication Rather than Thought” (2024); Griffiths et al., “Whither Symbols in the Era of Advanced Neural Networks?” (2023)


Image: Hanna Hur, Visitor v, 2024. Collection of The Museum of Modern Art, New York.