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Gary L. Drescher

Gary L. Drescher is an independent scholar and was recently Visiting Fellow at the Center for Cognitive Studies at Tufts University. He received his Ph.D. in computer science from MIT in 1989 and is the author of Made-Up Minds: A Constructivist Approach to Artificial Intelligence (MIT Press, 1991).

Titles by This Author

Demystifying Paradoxes from Physics to Ethics

In Good and Real, Gary Drescher examines a series of provocative paradoxes about consciousness, choice, ethics, quantum mechanics, and other topics, in an effort to reconcile a purely mechanical view of the universe with key aspects of our subjective impressions of our own existence.Many scientists suspect that the universe can ultimately be described by a simple (perhaps even deterministic) formalism; all that is real unfolds mechanically according to that formalism. But how, then, is it possible for us to be conscious, or to make genuine choices? And how can there be an ethical dimension to such choices? Drescher sketches computational models of consciousness, choice, and subjunctive reasoning--what would happen if this or that were to occur?--to show how such phenomena are compatible with a mechanical, even deterministic universe. Analyses of Newcomb's Problem (a paradox about choice) and the Prisoner's Dilemma (a paradox about self-interest vs. altruism, arguably reducible to Newcomb's Problem) help bring the problems and proposed solutions into focus. Regarding quantum mechanics, Drescher builds on Everett's relative-state formulation--but presenting a simplified formalism, accessible to laypersons--to argue that, contrary to some popular impressions, quantum mechanics is compatible with an objective, deterministic physical reality, and that there is no special connection between quantum phenomena and consciousness.In each of several disparate but intertwined topics ranging from physics to ethics, Drescher argues that a missing technical linchpin can make the quest for objectivity seem impossible, until the elusive technical fix is at hand.

A Constructivist Approach to Artificial Intelligence

Made-Up Minds addresses fundamental questions of learning and concept invention by means of an innovative computer program that is based on the cognitive-developmental theory of psychologist Jean Piaget. Drescher uses Piaget's theory as a source of inspiration for the design of an artificial cognitive system called the schema mechanism, and then uses the system to elaborate and test Piaget's theory. The approach is original enough that readers need not have extensive knowledge of artificial intelligence, and a chapter summarizing Piaget assists readers who lack a background in developmental psychology.

The schema mechanism learns from its experiences, expressing discoveries in its existing representational vocabulary, and extending that vocabulary with new concepts. A novel empirical learning technique, marginal attribution, can find results of an action that are obscure because each occurs rarely in general, although reliably under certain conditions. Drescher shows that several early milestones in the Piagetian infant's invention of the concept of persistent object can be replicated by the schema mechanism.