Epictetus 
The Golden Sayings of Epictetus, with the Hymn of Cleanthes [PDF ebook] 

Excerpt from Book:
If what philosophers say of the kinship of God and Man be true, what remains for men to do but as Socrates did:—never, when asked one’s country, to answer, ‘I am an Athenian or a Corinthian, ‘ but ‘I am a citizen of the world.’
If God had made that part of His own nature which He severed from Himself and gave to us, liable to be hindered or constrained either by Himself or any other, He would not have been God, nor would He have been taking care of us as He ought . . . . If you choose, you are free; if you choose, you need blame no man—accuse no man. All things will be at once according to your mind and according to the Mind of God.
Petrifaction is of two sorts. There is petrifaction of the understanding; and also of the sense of shame. This happens when a man obstinately refuses to acknowledge plain truths, and persists in maintaining what is self-contradictory. Most of us dread mortification of the body, and would spare no pains to escape anything of that kind. But of mortification of the soul we are utterly heedless. With regard, indeed, to the soul, if a man is in such a state as to be incapable of following or understanding anything, I grant you we do think him in a bad way. But mortification of the sense of shame and modesty we go so far as to dub strength of mind!