memory-belief is happening now, not in that past time to which the
belief is said to refer. It is not logically necessary to the existence
of a memory-belief that the event remembered should have occurred,
or even that the past should have existed at all. There is no logical
impossibility in the hypothesis that the world sprang into being five
minutes ago, exactly as it then was, with a population that "remembered"
a wholly unreal past. There is no logically necessary connection between
events at different times; therefore nothing that is happening now or
will happen in the future can disprove the hypothesis that the world
began five minutes ago. Hence the occurrences which are CALLED knowledge
of the past are logically independent of the past; they are wholly
analysable into present contents, which might, theoretically, be just
what they are even if no past had existed.

I am not suggesting that the non-existence of the past should be
entertained as a serious hypothesis. Like all sceptical hypotheses, it
is logically tenable, but uninteresting. All that I am doing is to use
its logical tenability as a help in the analysis of what occurs when we
remember.

In the second place, images without beliefs are insufficient to
constitute memory; and habits are still more insufficient. The
behaviourist, who attempts to make psychology a record of behaviour, has
to trust his memory in making the record. "Habit" is a concept involving
the occurrence of similar events at different times; if the behaviourist
feels confident that there is such a phenomenon as habit, that can only
be because he trusts his memory, when it assures him that there have
been other times. And the same applies to images. If we are to know as
it is supposed we do--that images are "copies," accurate or inaccurate,
of past events, something more than the mere occurrence of images must
go to constitute this knowledge. For their mere occurrence, by itself,
would not suggest any connection with anything that had happened before.

Can we constitute memory out of images together with suitable beliefs?
We may take it that memory-images, when they occur in true memory, are
(a) known to be copies, (b) sometimes known to be imperfect copies
(cf. footnote on previous page). How is it possible to know that a
memory-image is an imperfect copy, without having a more accurate copy
by which to replace it? This would SEEM to suggest that we have a way
of knowing the past whi