Computer models of human psychology are based on mathematical rules. It is a philosophical question whether the mind can ever be wholly explained by a finite set of mathematical equations. A new branch of philosophy called neurophilosophy endorses this view while the holistic tradition of William James, the Gestalt theorists, and the humanistic psychologists would argue that the whole is more than the sum of its parts. As of now, there is no definitive answer to this question. Another controversy regarding cognitive science and artificial intelligence involves the concept of qualia. This refers to the subjective quality of a mental process, the yellow of yellow, the sadness of sad. AI may well be able to model the neurological processes underlying the perception of the color yellow, but can it explain how these neuronal firing patterns produce the experience of yellow? At present, we simply do not know the answer to these fundamental philosophical questions.