In a Guide to the Good Life, William B. Irvine lays out the Trichotomy of Control.

You should be able to take any task, event, or goal that you hold yourself to, and place it into one of these three categories:

  1. Things over which you have complete control (such as the goals that you set for yourself)
  2. Things over which you have some but not total control (such as whether you come first in a go-kart race against your friends)
  3. Things over which you have no control at all (e.g. whether the tectonic plate that you're stood on continues to be stable this evening)

The Trichotomy of Control is a useful framework for evaluating the work on your plate, the goals that you set, and the way that you manage your life.

For example;

  • How much of your life is spent thinking about or pursuing events or outcomes over which you have no control at all?
  • Do your goals set you up for disappointment, even when you have made progress? Imagine you have just finished your first go-kart race, and you managed to come second place. Who is more content - (a) the person who set out to race to the best of their ability or (b) the person who set out to win the race?

Epictetus thought that focusing on what you can control was the chief task in life:

The chief task in life is simply this: to identify and separate matters so that I can say clearly to myself which are externals not under my control, and which have to do with the choices I actually control (Epictetus, Discourses, 2.5.4-5)