Everywhere and at all times it is in thy power piously to acquiesce in thy present condition, and to behave justly to those who are about thee, and to exert thy skill upon thy present thoughts, that nothing shall steal into them without being well examined.
Marcus Aurelius, Epictetus, Lucius Annaeus Seneca (2015). “Stoic Six Pack: Meditations of Marcus Aurelius The Golden Sayings Fragments and Discourses of Epictetus Letters from a Stoic and The Enchiridion”, p.41, Lulu.com