76 HENRY RUTGERS MARSHALL : memory-image. On the other hand, it has a certain complete- ness which does not belong to a (the so-called representation of A), which latter in comparison seems elusive and lacking in stability, a and H can thus not be identified in any sense. It is also clear that a is not a presentation again of S (what A was), and I myself can see no ground whatever for the assertion that a is a presentation again of A itself. Sec. 15. It appears then that, in the introspective experience of the recognition of what we call images or representations, we hav.e no evidence whatever that they are exact reproduc- tions of any previously existing presentations, and, therefore, the occurrence of these images or representations does not stand in opposition to the view already maintained that each presentation is a perfectly new one. Our use of terms is evolved out of the every-day needs of practical life. In this practical life we assume that the objects around us are what we call " the same " from moment to moment, although when we consider the matter carefully we know they cannot be actually so. It is only for con- venience and for practical utility that we assume this identity even of object as the source of successive primary presenta- tions and of their connected images or secondary presenta- tions. And even this assumption, useful as we ordinarily find it, not infrequently shows us its falsity by leading us into difficulties ; as, for instance, when the misunderstanding of a friend's action is acknowledgedly due to our failure to appreciate the change that has come over him with changed conditions that we cannot grasp. In a quite similar manner we assume that the primary presentations arising in connexion with successive experiences (and compared as secondary presentations in a new moment) are the same from moment to moment ; but it must be acknowledged that this assumption like the one first men- tioned is based, not upon any real permanency, but upon the needs of practical life. If we did not constantly react upon our environment just as if the secondary presentation of any one moment was what we call " the same " as the primary presentation of the previous moment just as if the primary presentation of one moment had what we speak of as some permanent elements which ran over into the secondary presentation of the next moment we should be unable to continue our existence as organic beings. It is this demand of practical life which has fastened upon us the crude notion that successive presentations are in some measure not always new and unique.
