For Proclus philosophical system is expressed in dianoetic terms. Thus while Proclus is a systematic thinker, the terms in which his system is written themselves fall short of the reality which they seek to express. Moreover, because dianoia is a thinking which never has a complete grasp on its object, the Procline system must be considered to be in principle incomplete. I will argue for this account of philosphical system in Proclus in the rest of this paper, through an examination of Eternity and Time in his philosophy.