I am richer than you, therefore my wealth is superior to yours’; and ‘I am a better speaker, therefore my diction is better than yours.’ But you are … - Epictetus

People with a strong physical constitution can tolerate extremes of hot and cold; people of strong mental health can handle anger, grief, joy and the other emotions.

Don’t let the force of an impression when it first hit you knock you off your feet; just say to it: Hold on a moment; let me see who you are and what you represent. Let me put you to the test.

Sickness is a problem for the body, not the mind — unless the mind decides that it is a problem. Lameness, too, is the body's problem, not the mind's. Say this to yourself whatever the circumstance and you will find without fail that the problem pertains to something else, not to you.