(To solve all these difficulties) it may be stated that nothing
hinders the admission that the actualization of the sensation produces
in memory an image, and that the imagination, which differs (from
sensation), possesses the power of preserving and recalling these
images. It is indeed imagination in which sensation culminates; and
when sensation ceases, imagination preserves its representation.
If then this power preserve the image of the absent object, it
constitutes memory.[149] According as the image remains for a longer
or shorter time, memory is or is not faithful; and our memories
last, or are effaced. Memory of sense-objects therefore belongs to
the imagination. If this faculty of memory be possessed by different
persons in unequal degrees, this difference depends either on the
difference of forces, or on practice (or exercise), or on the absence
or presence of certain bodily dispositions which may or may not
influence memory, or disturb it.[150] But elsewhere we shall study the
question further.