an intelligible account can be given, are spatial relations of co-momentary parts of Experience; the type of instantaneous space is once and for all given by the ordering of the moment to which it belongs, and which determines its differentiation from, or analogy with, the spaces of other moments of the same Experience.
36. From our definition of a spatial relation it is evident that spatial relations can be predicated as existing only between parts of the same moment. In spite of that, however, we are accustomed to speak of spatial relations between two events which are not co-momentary, thereby implying that the content and ordering of two distinct (not identical) moments are comparable. Such a comparison is in actuality rendered possible by the fact that moments of a given Experience constitute a psychologically continuous series; in a given psychological instant (specious present) there is present to the mind a whole series of very “near” moments, not at all clearly distinguishable from one another, which not only makes it possible to compare the content and ordering of moments in close proximity, but enables us to create a certain kind of space common to more moments than one and to speak of change of position (movement) as a reality given by immediate perception.
37. It would, however, be very difficult for the percipient mind to keep its bearings in an uninterrupted stream of events and to compare more distant moments (moments, that is, which are outside the mind’s field of vision in a given “psychological instant”) through the mediation of all the moments which fill the interval between them in its Experience.
Temporally, different parts of the mind vary, figuratively speaking, in the clearness with which they are apprehended by the mind: perceptions “present,” with those immediately adjacent in past and future (for in a given psychological instant the mind actually anticipates the perceptions of the immediate future) are the clearest, and this clearness is subject to a progressive diminution which is gradual with the past and very rapid with the future. Out of the past and the future there emerge only those swarms of perceptions which remain “the same” in a finite section of the time series of Experience, which, in other words, endure. The mind, we may say, has a special preference for permanence, for what in the ever changing stream of Experience remains the same; and following this preference, or actuated by this necessity, it looks for those properties and relations in Experience which endure.
