ld involve a greater
interval between any two images than that between the corresponding
experiences.

[121] I need hardly say that there is no sharp distinction between these
two modes of subjective appreciation. Our estimate of an interval as it
passes is really made up of a number of renewed anticipations and
recollections of the successive experiences. Yet we can say broadly that
this is a prospective estimate, while that which is formed when the
period has quite expired must be altogether retrospective.

[122] See an interesting paper on "Consciousness of Time," by Mr. G. J.
Romanes, in _Mind_ (July, 1878).

[123] It is well known that there is, from the first, a gradual falling
off in the strength of a sensation of light when a moderately bright
object is looked at.

[124] _Cf._ Hartley, _Observations on Man_, Part I. ch. iii. sec. 4
(fifth edit., p. 391).

[125] See Dr. Carpenter's _Mental Physiology_, fourth edit, p. 456.

[126] This is, perhaps, what is meant by saying that people recall their
past enjoyments more readily than their sufferings. Yet much seems to
turn on temperament and emotional peculiarities. (For a fuller
discussion of the point, see my _Pessimism_, p. 344.)

[127] The only exception to this that I can think of is to be found in
the power which I, at least, possess, after looking at a new object, of
representing it as a familiar one. Yet this may be explained by saying
that in the case of every object which is clearly apprehended there must
be vague revivals of _similar_ objects perceived before. Oases in which
recent experiences tend, owing to their peculiar nature, very rapidly to
assume the appearance of old events, will be considered presently.

[128] _Mental Physiology_, p. 456.

[129] _Mental Physiology_, second edit., p. 172.

[130] _Loc. cit._, p. 390.

[131] This source of error has not escaped the notice of autobiographers
themselves. See the remarks of Goethe in the opening passages of his
_Wahrheit und Dichtung_.

[132] One wonders whether those persons who, in consequence of an injury
to their brain, periodically pass from a normal into an abnormal
condition of mind, in each of which there is little or no memory of the
contents of the other state, complete their idea of personal continuity
in each state by the same kind of process as that described in the text.

[133] The reader will remark that this condition of clear intellectual
consciousness, namely, a certain