Memento Mori
The Roman general riding through his triumph, the parade of captives behind him and the cheering crowds on either side, supposedly had a slave at his shoulder whose only job was to whisper, at intervals, memento mori. Remember you will die. Whether the practice was historical or invented later, the instinct behind it was old and durable. The greatest moment of a person’s life was, in the Roman moral imagination, exactly the moment that most needed the corrective. You are mortal. This will pass. The version of you being celebrated today will be a name on a tomb soon enough, and forgotten not long after that. It was meant to be heard, and it was meant to be ignored at one’s peril.
Marcus Aurelius wrote it to himself almost daily. Thou mayest leave life this very moment: let this regulate every act and thought. Seneca, in the Letters to Lucilius, returned to the theme so often it became almost a tic. The medieval Christians built whole genres of art around it — the danse macabre, the skull on the scholar’s desk, the vanitas still life with the time-worm crawling from the fruit. The Buddhists had their own version: the corpse meditation, in which the practitioner sat at a charnel ground and watched a body decompose over weeks, on the disciplined assumption that this was the most useful thing he could be doing with his afternoon.
What every tradition was after was the same: a felt apprehension of mortality strong enough to reorder the priorities that the day-to-day mind reorders away from. Most cognitive resources are spent on threats and rewards on a timescale of hours and weeks. Death is on a timescale of decades, and the part of you that plans for it, when it plans at all, plans abstractly. Memento mori is the deliberate practice of dragging the abstraction into present awareness, where it can do the work of telling you that the meeting you are dreading and the email you are obsessing over are not, by the standard you would use on your deathbed, what your remaining time should be spent on.
The practice is uncomfortable, which is the point. Heidegger argued in Being and Time that human existence is structured by the awareness of its own finitude — that what makes a life yours is the fact that it ends, and ends specifically — and that most cultural machinery exists precisely to obscure this from the person whose life it is. He called the obscuring das Man: the anonymous “they” who arrange entertainment, distraction, and busy-ness in dense enough layers that the question of one’s mortality can be deferred indefinitely. The Romans needed a slave to whisper. We have whole industries that whisper the opposite, twenty-four hours a day, and the corrective has to be installed against significant headwind.
Deep time is the cosmological version of the same lesson. Hyperbolic discounting is the cognitive failure mode the practice exists to correct. Neither gives memento mori its personal stakes, which only show up when the abstraction stops being a concept and becomes the small daily recognition that today is one of a finite and unknown number of remaining days.
Once a day, do the calculation. If you live as long as your grandparents, you have approximately N days left. N is much smaller than you think, and a substantial fraction of it will be spent on sleep, traffic, and the management of obligations no one will remember. Of what remains, what fraction are you willing to spend on the thing you spent today on? If the answer is most of it, the practice has done nothing for you and you do not need it. If the answer is less than I am currently spending, the slave has done his job. What you do with that information is your own.