 Averroes disagreed with Avicenna on a number of topics concerning faculty psychology, for example: on the organ and medium of touch, on the material or immaterial transmission of odors, and on whether human beings have an estimative faculty or not. These controversies were continued in the Latin tradition. The most influential pieces of psychological doctrine imported from the Arabs probably were Avicenna’s theory of estimation (wahm), his theory of potential, acquired and active intellects, and Averroes’ thesis that there is one intellect for all human beings.