Abstract

William of Ockham held in his career two different theories about the nature of concepts. According to the first theory, concepts are forged by the mind and "terminate" the mental acts which produce them. This so called "fictum"-theory was abandoned, and Ockham held another theory, according to which concepts are identified with the mental acts themselves. While I think this is a correct description of the evolution of his philosophy, there is one aspect that has gone so far unnoticed : in his later theory, not only concepts do not terminate mental acts, but nothing seems fit to play this role. Mental acts are no longer "terminated" by anything. Therefore, as the theory of concepts changes, there is also a change in the theory of mental acts. This last change explains the disappearance of the vocabulary associated with the verb "terminare" in the exposition of the mental act theory.