They believe that when time is portrayed as dimensional, it is a misrepresentation of reality. Process philosophers hold the popular belief that the future is undetermined, open - a clean slate, so to speak. To philosophers of the manifold, the advance of humans through time is believed to be a sort of illusion. Philosophers of the manifold, in opposition of process philosophers, claim that words such as past and future are inadequate when describing time because they are indexical references that "refer to the act of their own utterance" ("time"). Philosophers of the manifold also hold that any changes in respect to past and future are not true predicates of events. To these philosophers, neither the future nor the past can be changed or altered because, according to the philosophers of the manifold, neither past or future really exist - time is always now, always occurring in the present. Philosophers of the manifold make it clear that while they believe in the determinatedness of the future, they remain completely neutral on the subject of determinism, the theory that there are laws whereby later states of the universe may be deduced from earlier states. In summation, philosophers of the manifold claim that time itself always exists in the present, because time itself knows only the present. Time has no history or future because it simply exists. (Humans are the ones that have an origination and termination, not time.).
Regardless of the agreed upon definition of time, the philosophy involved in the comprehension of time truly does weigh heavily on the human psyche. Humans regret the past and fear the future because they are swept up and bound by their own impositions of time. Humans are forced to admit that time is irreversible and the passage of humans through time is inexorable because they are constantly reminded of impending death. There are two general interpretations regarding time and human observation of time.