The Stoics believed in confronting the fear of physical death by visualizing it in such detail until it no longer carried the power to terrify. This was promoted by Epictetus and popularized by Marcus Aurelius in the 2nd century CE. It carried down to the 6th century, as Parker Palmer explained: “The Rule of Saint Benedict, that ancient guide to the monastic life, includes the admonition to ‘keep death before one’s eyes daily.’”
A dissenting view from Nikki Stern:
"Those who suffer from posttraumatic stress can’t shut off their mental tape. No, none of us needs help in picturing death.
It’s a little unnerving not to know what death might feel like or when it might visit. But I don’t obsess about it, just as I have no sense of what follows. It could be anything — reincarnation, paradise, or conversion into pure energy and a free trip around the universe. In any case, death doesn’t terrorize me — at least not my own.
Dying is another matter.”
Whether or not we visualize the unwanted and unappealing, we must also visualize more positively what we strive for in life, as Mark Manson described:
"Death is the only thing we can know with any certainty. And as such, it must be the compass by which we orient all of our other values and decisions. It is the correct answer to all of the questions we should ask but never do. The only way to be comfortable with death is to understand and see yourself as something bigger than yourself; to choose values that stretch beyond serving yourself, that are simple and immediate and controllable and tolerant of the chaotic world around you. This is the basic root of all happiness."
Parker J. Palmer. A Hidden Wholeness: The Journey Toward an Undivided Life. San Francisco: Jossey-Bass, 2004. p. 161.
Nikki Stern. Hope in Small Doses: Reasonable Happiness in Unreasonable Times. Humanist Press, 2012.
Mark Manson. The Subtle Art of Not Giving a F*ck: A Counterintuitive Approach to Living a Good Life. HarperOne, 2016. p. 206.