But in the region of the feelings this comparison is impossible, because two subjective states, of which one is the original and one the copy, cannot co-exist in the same individual, and because the primary impression cannot be objectivised. I see but one way of getting over the difficulty so as to arrive at an approximately correct answer. This would consist in comparing the revived emotional state with a written document dating from the moment of the first impression; and even this impression is open to doubt. J. J. Rousseau, speaking of the enthusiasm aroused by the love-letters of the _Nouvelle Héloïse_, tells us that they were inspired by his own love for Madame d’Houdetot, and adds, “What would they have said could they have read the originals!” It is possible that Rousseau was more or less mistaken; but this is a comparison of the kind I am suggesting. A correspondent, well equipped for psychological observations, and accustomed to note down the day’s impressions, had promised me to attempt such a comparison between the actual recollection and the written document; but various causes have prevented the accomplishment of this purpose. One might possibly, without much trouble, chance to recover a letter written under the impression of the moment, and compare it with the present emotional recollection which, rightly or wrongly, we consider most correct. For my part, I am inclined to doubt whether, in the case of feelings, there is ever a complete correspondence between the original and the copy; but this is merely a hypothetical view. It still remains to say a few words on forgetfulness in the region of the emotions. Affective amnesia is found in two forms—one pathological, the other normal. I pass over in silence the morbid manifestations, whose study would be both extensive and curious, but would lead me away from my principal aim, which is a practical one. We find numerous examples of the loss of altruistic, moral, or religious feelings, of partial or total indifference to the past, of complete insensibility—the _Gemütslosigkeit_ of the German alienists.