Memento Mori

The Stoics practised two exercises that sound grim and are not. One is premeditatio malorum, the premeditation of evils: deliberately imagining, in specific detail, the setbacks that might come. The other is memento mori, remember you will die. Both look like recipes for anxiety. Both were designed to remove it.

Take the rehearsal first. Seneca's observation is that what actually wounds is the unexpected. A blow you have already considered arrives as something you thought about; a blow you assumed could never come arrives as an ambush, and the shock is a large part of the damage. So he recommends running through the specifics in advance. Not vaguely, which is just worry, but concretely: what would I actually do, what would actually be left, how would the days actually go.

The structure survives intact in modern practice. A project premortem asks a team to imagine the launch has already failed and work backwards to explain why. Everyone knows the exercise is hypothetical and it still surfaces risks that a forward-looking plan misses, because imagining a failure that has happened is cognitively different from listing risks that might.

The distinction that keeps this from being rumination is that the rehearsal is deliberate and bounded. You choose to run it, you run it, you stop. Rumination is involuntary and does not stop. That line is real, and it is thin enough that the practice can tip into the thing it was meant to prevent, which is worth knowing before you adopt it.

Now the second exercise, which is larger. Marcus Aurelius returns to death constantly in the Meditations, and the purpose is never dread. It is prioritisation. If you could leave at any moment, the question of what deserves the time you have stops being abstract. He uses it mainly against two things: procrastination, which assumes a supply of days nobody has been promised, and resentment, which spends those days on people who will also shortly be dead.

He has one argument about death that is genuinely surprising, and it cuts against how everyone feels about it. However long you live, he says, you can only ever lose the present moment. The past is already gone and cannot be taken from you. The future was never yours to lose. So the person who dies at eighty and the person who dies at twenty are deprived of exactly the same thing: this instant, the only one anybody ever holds. On that argument the length of a life matters far less than it seems to.

Seneca makes the complementary point about time in On the Shortness of Life, and his version has more bite because it is an accusation. We are not given a short life, he says; we make it short. People guard money ferociously and hand their days to anyone who asks for them. They postpone what matters until a retirement that may not arrive. He points out that a man who would chase a missing coin across a room will lose an entire year without comment.

The uncomfortable exercise implied by that is to audit a week the way you would audit an account: hour by hour, marking which hours went on something you chose and which went on somebody else's business. Almost nobody has done it. Seneca's claim is that the result is what actually explains the feeling that life is passing quickly, and that the feeling is not a fact about time but a fact about spending.