But in dying, which is the greatest work we have to do, practice can give us no assistance at all. A man may by custom fortify himself against pain, shame, necessity, and such-like accidents, but as to death, we can experiment it but once, and are all apprentices when we come to it. There have, anciently, been men so excellent managers of their time that they have tried even in death itself to relish and taste it, and who have bent their utmost faculties of mind to discover what this passage is, but they are none of them come back to tell us the news....
Julius Canus, a noble Roman, of singular constancy and virtue, having been condemned to die by that worthless fellow Caligula, besides many marvellous testimonies that he gave of his resolution, as he was just going to receive the stroke of the executioner, was asked by a philosopher, a friend of his: “Well, Canus, whereabout is your soul now? what is she doing? What are you thinking of?”--“I was thinking,” replied the other, “to keep myself ready, and the faculties of my mind full settled and fixed, to try if in this short and quick instant of death, I could perceive the motion of the soul when she parts from the body, and whether she has any sentiment at the separation, that I may after come again if I can, to acquaint my friends with it.”
Michel de Montaigne