The Prehistory of Android Epistemology

2. The Prehistory of Android Epistemology Clark Glymour, Kenneth Ford, and Patrick Hayes

3. 1. Introduction • Android epistemology : • an exploration of the principles underlying the cognitive behavior of any possible kind of mechanical agents • AI : • disciplined by the limits of mechanical computation • AI and Philosophy • survey of the philosophical sources of contemporary ideas about AI

4. 2. Back to the Greeks : Plato and Aristotle • The object of knowledge • formal structure : finite combination of properties • e.g.) Man = (rational, animal), Triangle = (closed, retilinear, figure, three-sided) • all knowledge consists of knowing such combinations of forms of essential attributes of a thing or kind • In the Meno, “What is virtue?” • How to recognize the correct answer? • Everyone already knows implicitly at birth all of the laws of forms. • Middle Age : Method for acquiring knowledge : analysis & synthesis

5. 3. Ramon Lull and the Infidels • The study of God • Fundamental properties of God, and the combinations of His attributes • by means of appropriate machines • Lullian machine • to present the combinations of God’s virtues • each on camerae denote an attribute of God • nonmathematical reasoning can be done by a mechanical process • reasoning proceeds by combinatorics, not only by syllogism

6. 4. Computation and Discovery in the 17th Century :Pascal, Leibniz, and Bacon • Pascal : Pascaline • automatic calculating machine • remark : “The arithmetical machine produces effects which approach nearer, to thought than all the actions of animals.” • the calculator lacked will

7. 4. Computation and Discovery in the 17th Century :Leibniz • Substance & Concept • A substance just is a combination of attributes. • Whatever properties a substance has, it has necessarily. • Every concept just is a list or combination of primitive concepts. • Proof proposition : • Every proposition consists of a predicate applied to a subject. • Every ‘true’ proposition can be given a proof : identity A = A 1. Producing the combinations of simple concepts in subject/predicate 2. Showing the concept of the predicate is included in the concept of the subject, or vice-versa

8. 4. Computation and Discovery in the 17th Century :Leibniz • Envisioned the creation of universal dictionary • A concept simply is a combination of all that is known about it • Bar-Hillel(1950s) : in order to distinguish ambiguities, a huge database of all human knowledge is needed  reductio ad absurdum argument • Universal Dictionary : • express each concept in terms of the simplest concepts(1st part) • the production of scientific knowledge would become automatic • Algebraic way: mathematics of reason • an algorithm could be found for giving proofs(2nd part) : treat the problem as though it is part of algebra • represent each term as a symbol, and use algebraic method to search for identities.

9. 4. Computation and Discovery in the 17th Century :Leibniz • Computational Difficulty • Search space of reasoning expand too rapidly • require dictionaries of heuristics • The implementation : Stepped Reckoner • Binary inspiration : • a binary notation would permit a much simpler mechanism • natural proof of the existence of God : omniscient one(1), created everything out of nothing(0) • Significance • manipulating symbols • in combinatoric terms • not restricted to arithmetic

10. 4. Computation and Discovery in the 17th Century :Bacon • The inductive method for the new science • Discovery procedure : in search of the “form” of a phenomenon • a conjunction of features essential/necessary/sufficient for the phenomenon • Collect positive instances of the phenomenon • Collect negative instances of the phenomenon • find whatever combination of features is common to all positive instances, absent from all negative instances, and concomittant in degree with the degree of the phenomenon in the table of degrees • inspired the “concept learning” in cognitive psychology

11. 5. The Cartesian Way • Algebraic geometry • geometrical formalism  systems of algebraic equations • Cartesian conception of Mind • not a material device • entirely different substance that matter • close to the modern conception of software (something like a pattern or a specification, not substance)

12. 5. The Cartesian Way (Cont’d) • Influence : against the AI 1. Procedures,algorithms, methods, rules are inextricable from meaning and intention • rules for inquiry are not mechanical • rules in terms for which there are only inner criteria 2. Criterion for possibility : imagination • if p is imagined, then p is possible. if ~p is imagined, then p is not necessary • sows considerable confusion, like Searle’s Chinese room argument.

13. 6. Minds and Procedures: Hobbes to Kant • Hobbes • Reasoning is a psychological process • Representations can have an encoding by, or be analogous to, numbers. • Theory of reasoning is a theory of appropriate combinations • Mind: composed of particles( symbols, combined or decomposed in reasoning) • Locke, Hume, Mill, Maudsley • mental procedures • in which mental objects(ideas) are linked or associated. • Avoid Hobbes mechanical formulations • explained in terms of “similarity” and “vivacity” and temporal proximity of occurrence of ideas

14. 6. Minds and Procedures: Hobbes to Kant • Kant • few hints that mental processes are computational • father of the notion of top-down processing • The logical theory can’t account for mathematical inference • Mathematics and much else is known a priori, not derived from inductions founded on experience. • The content of experience is a function of the procedures of mind, and of unknowable features of things in themselves. • As procedures that automatically construct the content of experience from the deliverance of sense.

15. 7. The 19th Centry: Boole, Frege and Freud • Boole • algebra of logic : algebra is important because it provides a method for correct reasoning • mathematical theory of reasoning as a description of psychological laws of nature • realized the contradiction : human make errors of reasoning • Frege • the first adequate formulation of the logic of proposition : formalized a system of logic including both first-order logic and the quantification over properties • one of the principal tools for the study of android epistemology

16. 7. The 19th Centry: Boole, Frege and Freud • 19~20c • 2 ways : symbolic vs. connectionist (structure of reasoning vs. brain-like architectures) • Emerging connectionist models of computations • by the late 19th century, among neuropsychologists. • Freud(1895) : unpublished Project for a Scientific Psychology • Hebb(1949): The organization of Behavior • Symbolic tradition • What might be Kant’s ‘construction’ or ‘systhesis’? • Russel and Carnap : Frege’s logic in combination with set theory, can be used to describe the construction of physical objects from the data of sensation.

17. 7. The 19th Centry: Boole, Frege and Freud • Russel’s idea • variables ranging over basic entities(the sense data) • predicates denoting properties of sense data  define terms denoting sets of sense data • physical objects: sets of, sets of sets of, …. sense data • Late in his life, in Human Knowledge, Its Scope and Limits: • abandon the idea of building up the world from sense data • considers the general knowledge of kinds and causes that systems must innately have in order to convert sensation into knowledge of the world

18. 7. The 19th Centry: Boole, Frege and Freud • Carnap • The Logical Structure of the World(1928) • not only as a collection of logical formulas • construction as a computational procedure • fictitious procedure : how to calculate a representation of the object constructed from any list of pairs of elementary experiences • the first philosopher to present a theory of mind as a computational program • inspired by Ramsey(1920s)’s the subjective utility theory and the theory of measurement of subjective utilities • inductive norms as the design principles for an android that would begin life with some probability distribution and carry on by conditioning on the evidence it acquired throughout life

19. 8. Conclusion • The development of methods for representing information in a physical form • AI : • re-establishing the cooperation between philosophy and engineering • now with richer tools • new kind of machines : physical computing machine, and ‘virtual’ machines(software) • Modern android epistemology: • rely substantially on independent work in philosophical logic and philosophy of science • requires : rigor and imagination, clarity of broad motive, clarity of detail, willinness to take off the blinkers of disciplines