Thcsc are the problems of investigating theories and techniques of natural and artificial psychologies by means of t,he most fit mathematical concepts. Rational psychology should not, be confused with logic-based presentations of artificial intelligence. While investigations based on mathematical logic are relatively familiar and certainly useful, using only that portion of mathematics to characterize psychologies presupposes that psychological questions are fundamentally logical. That presupposition is not, ncccssary for the development of an exact science of mind. Rational Psychology Hat,ional psychology is a part of mathematics, the conceptual investigation of psychology.

We compare the big problems studied in artificial intelligence and related fields in order to understand some major changes--both internal and external--recently suffered by AI. The comparison finds AI with few problems to call its own, and we identify some further major changes that may occur soon. Work in earlier days seemed heroic, filled with the excitement of being first to discover and conquer big problems, while much work today seems a bland pursuit of more of the same. Where, the old hands ask, have all the big ideas gone? This note attempts to respond to this complaint, for the answer sheds light on the nature of artificial intelligence.

Rational psychology is the conceptual investigation of psychology by means of the most fit mathematical concepts. Several practical benefits should accrue from its recognition.

GLISP is a high-level language that is complied into LISP. It provides a versatile abstract-data-type facility with hierarchical inheritance of properties and object-centered programming. GLISP programs are shorter and more readable than equivalent LISP programs. The object code produced by GLISP is optimized, making it about as efficient as handwritten Lisp. An integrated programming environment is provided, including automatic incremental compilation, interpretive programming features, and an intelligent display-based inspector/editor for data and data-type descriptions. GLISP code is relatively portable; the compiler and data inspector are implemented for most major dialects of LISP and are available free or at nominal cost.