Catania, A. C. (1999). Thorndike's legacy: Learning, selection, and the law of effect. Journal of the Experimental Analysis of Behavior, 72, 425-428.

This introduction to a symposium on the centennial of Edward L. Thorndike's 1898 monograph on animal intelligence briefly considers the origins of his law of effect and the influence of Darwin's selectionism. It also provides the background for an unfinished book review by William W. Cumming of a biography of Thorndike. The review places in historical context Thorndike's position both on psychology as a science of behavior and on the vocabulary of that science.

Key words: E. L. Thorndike, Animal Intelligence monograph, law of effect, learning theories, associationism, Charles Darwin, selectionism