Laudator Temporis Acti

Alexander Murray, Suicide in the Middle Ages, Vol. I: The Violent against Themselves (Oxford: Oxford University Press, 1998), p. 47:

Astronomers, aware that their means of cognition, light, is subject to the laws they are trying to deduce from what it tells them, have deduced that the cosmos itself contains such zones of impenetrable darkness. They call them black holes, and explain how, in them, gravitational force is too great, for light cannot escape, so that we can never see into them, only calculate their existence from the behaviour of light near their edge. History has its black holes. I do not mean the massive, natural ephemerality of most human thoughts and actions, in which those remembered or recorded form rare exceptions, stars in a black sky. I mean categories of thought and action innately antithetical to record, which hide from it as from an enemy. Among many examples of which historians have become aware is sacramental confession to a priest. If the penitent's words were recorded or remembered his sins would be put behind him less effectively. It is easy to think of other examples.

In the European Middle Ages, suicide is one. In searching for it, that is to say, we have to expect a historical black hole, and look for events in the act of vanishing into it.