Abercrombie, the most learned analyst of the mind since Reid and Stewart, has four varieties of the dream:
1st. From wrong association of new events.
2nd. Trains of thought from bodily association.
3rd. Revival of old associations.
4th. Casual fulfilment of a dream!
You perceive the first and third are merely memory, with right and wrong arrangements; the second, excitement of ideas from present sensations; the fourth, if it be not a mere coincidence, is the result, as I have explained, of imparted impetus, or deep thinking on subjects presented to the mind. The eccentricities of dreaming are not more curious than those of the reminiscent faculty when awake; indeed, memory itself may seem to be sometimes dreaming, and at others even fast asleep. Those who survived the plague in Athens (as we read in Thucydides), lost for a time the recollection of names, their own and those of their friends, and did not regain it until their health was re-established.
Mori, during his frequent moods of excitement, quite lost his memory of music, so that, for many minutes, he could neither read a note nor play from memory.
There have been persons who have very suddenly forgotten their own names, which they were about to announce on a visit to a friend.
“Mr. Von B——, envoy to Madrid, and afterwards to Petersburg, a man of a serious turn of mind, yet by no means hypochondriacal, went out one morning to pay a number of visits. Among other houses at which he called, there was one where he suspected the servants did not know him, and where he consequently was under the necessity of giving in his name, but this very name he had at that moment entirely forgotten. Turning round immediately to a gentleman who accompanied him, he said, with much earnestness, ‘For God’s sake, tell me who I am.’ The question excited laughter, but as Mr. Von B—— insisted on being answered, adding that he had entirely forgotten his own name, he was told it; upon which he finished his visit.”
The eccentric impressions of this faculty will be often intermittent, or marked by sudden yet regular remissions.