[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 degree of similarity and continuity of character in our successive mental states, is complementary to the other condition, constant change, already referred to.  It may, perhaps, be said that all clear consciousness lies between two extremes of excessive sameness and excessive difference.

[134] It follows that any great transformation of our environment may lead to a partial confusion with respect to self.  For not only do great and violent changes in our surroundings beget profound changes in our feelings and ideas, but since the idea of self is under one of its aspects essentially that of a relation to not-self, any great revolution in the one term, will confuse the recognition of the other.  This fact is expressed in the common expression that we “lose ourselves” when in unfamiliar surroundings, and the process of orientation, or “taking our bearings,” fails.

[135] On these disturbances of memory and self-recognition in insanity, see Griesinger, op. cit., pp. 49-51; also Ribot, “Des Desordres Generaux de la Memoire,” in the Revue Philosophique, August, 1880.  It is related by Leuret (Fragments Psych. sur la Folie, p. 277) that a patient spoke of his former self as “la personne de moi-meme.”