What we can and cannot control.
The Enchiridion was written by the Roman-era Greek philosopher Epictetus on Stoic ethics. In the writing, which is only 20 pages, Epictetus lays out axioms on how one ought to act and especially as a philosopher. One of the overarching concerns Epictetus showed in his writing was that of control – understanding when we do and do not have control over the changes in our life. On this subject, Epictetus gave examples on when annoyances and grievances should honestly affect us; it is only when they do affect us, and when we are the point of control, should we be bothered.
Epictetus sought to point his readers in the direction of happiness through apathy and a large amount of this is knowing when to be affected by external stimuli, this would also include what has been given to the subject (in Epictetus’ case of a bad father, we are only rightly given a father by nature and not one that has been demanded to be good). In a very Buddhist sense, Epictetus urged his readers to become liquid to anything that may be deemed “bad” and to look beyond this state and into one where we cannot be bothered by it.