Source: John Sellars, Stoicism (Berkeley: University of California Press, 2006) 66.
"According to Gellius' account, the passage from Epictetus said the following. It argued that the impressions we receive that present external objects to us are not within our control. We do not have the power to choose them; instead they force themselves on us. However, we do have the power to choose whether to assent to these impressions or not. But in a situation such as the storm at sea, the mind of even the Stoic sage will be disturbed by the sudden impressions it receives against its will. In an interesting discussion of Gellius' account, Augustine glosses this point by saying that it is as if the resulting emotion is just too quick for the mind (De Civitate Dei 9.4.2). However, although the Stoic philosopher might be briefly overcome by the force of the sudden impression, he will not give his assent to the impression. Instead he will stand firm, reject the impression that something terrible is happening, and affirm that in fact nothing bad has occurred. In contrast, the other passengers in the storm will unthinkingly assent to the impression that something terrible is indeed happening."
If a storm at sea strikes, even a Stoic will be afraid, at least for a little while. That's human nature. Sure, because life is so hard, there have been times when I've thought that I wouldn't care that much if my life were endangered. But I shake when I think about being at a high point and possibly falling. The thought of drowning scares me. So I can understand why someone would be afraid of a storm at sea. The vulnerability of a person at that moment, as a storm threatens to tear up his very ground amidst a vast body of water! I shudder to think about it.
This quote on the Stoic at sea reminds me of things I've seen in Christianity. One evangelical told me that a true Christian should have a resolute faith in God, even if he were hanging over Niagra Falls. I'm sure she'd recognize that even a strong Christian would be afraid in that sort of situation, but she'd probably go on to say that he would overcome such fear as he clung to his faith.
Acts 27 is the story of Paul in the midst of the sea-storm. An angel tells him that everything will be all right, Paul then eats before the other passengers with utter peace, and the passengers begin to take comfort. I kind of like this. The quote on Stoicism reminds me of what I see in evangelicalism: "Look at me! I'm at peace in this difficult situation. Those heathens are not. Nyah nyah nyah nyah nyah." But Acts 27 actually shows Paul giving encouragement and comfort to those very "heathens." He's at peace, but not only for his own sake.
But even Paul had to deal with fear, as II Corinthians 7:5 states: "For even when we came into Macedonia, our bodies had no rest, but we were afflicted in every way--disputes without and fears within" (NRSV). And he had every reason to be afraid, with all the people trying to kill him and the storms at sea he continually encountered. But he found a way to be courageous through all of his fears. What gave him strength was his realization that nothing in creation could separate him from the love of God in Jesus Christ his Lord (Romans 8:35-39). As he said to his shipmates in the midst of the storm, he belonged to God (Acts 27:23).