  What are some features whose intuitive temporal asymmetry we think of as, perhaps, “constituting” the asymmetrical nature of time? There are asymmetries of knowledge: We have memories and records of the past, but not of the future. There are asymmetries of determination: We think of causation as going from past through present to future, and not of going the other way round. There are asymmetries of concern: We may regret the past, but we anxiously anticipate the future. There are alleged asymmetries of “determinateness” of reality: It is sometimes claimed that past and present have determinate reality, but that the future, being a realm of mere possibilities, has no such determinate being at all.