How did the Stoics practice the evening review?

Seneca describes the practice in a letter to Lucilius. He tells Lucilius that he will report each day's conduct in sequence, and explains why: "I shall keep watching myself continually, and, a most useful habit, shall review each day" (Moral Letters Vol II 83.2). He gives a reason that is easy to miss. Most people fail morally not because they lack good intentions for the future but because they never look back. "This is what makes us wicked: that no one of us looks back over his own life. Our thoughts are devoted only to what we are about to do" (Moral Letters Vol II 83.2). Planning is empty without review, since our plans for the future depend on the past we have actually lived.

Notice the standard Seneca sets for himself. He writes as if living in plain sight of everyone, and thinking as if someone could see into his inmost soul, because for him there is such a witness: "Nothing is shut off from the sight of God. He is witness of our souls" (Moral Letters Vol II 83.1). The review is not a private accounting trick. It is conducted as if under observation, which raises the stakes of honesty with yourself.

Epictetus gives a companion practice, and here the common misreading needs correcting first. The evening review is often pictured as a kind of moral diary, a warm reflection on the day's feelings. Epictetus's version is closer to a drill for a specific skill. He tells his students to keep the right opinions ready for each occasion, breakfast, the bath, bed, the way a craftsman keeps tools ready for each job (Discourses III 10). The nightly version of this readiness is a set of verses he has his students hold in mind, not to recite aloud like a chant, but to actually use: "Let sleep not come upon your languid eyes before each daily action you have scann'd; what's done amiss, what done, what left undone; from first to last examine all, and then blame what is wrong, in what is right rejoice" (Discourses III 10).

Read closely, the instruction has three parts, not one. Scan the whole day's actions. Sort them: what was done wrong, what was done well, what was left undone. Then respond in kind, blame for the wrong and something like rejoicing for the right. Epictetus is explicit that the point is not to have the words on your lips but to have the opinions in readiness, the way you already have opinions about a fever ready before the fever starts (Discourses III 10). The review at night trains you to have the right judgments in hand during the day, when it counts.

What changes for someone who takes this seriously is the object of attention. You are not reviewing how the day made you feel. You are reviewing your own actions and the judgments behind them, because for Epictetus only your own judgments, desires, and actions are up to you (Handbook 1). A day reviewed this way asks a narrow question three times over: given what was and was not up to me, did I judge and act well. That is a different exercise from asking whether the day was pleasant.

One concrete way to apply this: at night, before sleep, go through the day's actions in order, and for each one ask only whether it was up to you and whether you handled it well, not how it turned out. Where you judged or acted badly, name it plainly. Where you did well, let that stand too. Then stop. The value of the exercise is in the seeing, not in punishing yourself afterward.