Exploring why clinical textbooks oen carry historical chapters can be informative. One common reason for such addition is fashion. Although for some time now such chapters are almost de rigueur, editors vary in what they want. Some just want lists of achievements as a celebration of scientic progress and this task is best met by retired clinicians. Others go further and ask for a sort of meta-analysis of historical papers; in practice, this leads to requesting ‘updated’ chapters for each new edition of the textbook. Going further a third group of editors considers them a necessity. eir view is correct because symptoms and disorders are inherently historical; that is, objects constructed in a semantic space and made temporarily stable by means of specic social narratives networks neurobiological correlations. In the case in hand, history has shown that all narratives about dementia have been: (1) born in specic historical convergences and (2) considered as ‘true’ during the time they were socially predominant.