Rufus. From the remarks of Epictetus on friendship
Of the things that exist, God has put some in our control, others not in our control. In our control he has put the noblest and most excellent part by reason of which He is Himself happy, the power of using our impressions. For when this is correctly used, it means serenity, cheerfulness, constancy; it also means justice and law and self-control and virtue as a whole. But all other things He has not put in our control. Therefore we ought to become of like mind with God and, dividing things in like manner, we ought in every way to lay claim to the things that are in our control, but what is not in our control we ought to entrust to the universe and gladly yield to it whether it asks for our children, our country, our body, or anything whatsoever.