Possible Clues:

• Endure endlessly without love? One can't complain
• Not terminally ill, about to become indifferent to pain
• Long-suffering Saint Oswald's first to join leaders in island church
• One who endures hardship uncomplainingly
• Long-suffering type; follower of Zeno
• One resigned when about to get endlessly ill
• Philosopher thus holding the office, initially
• Hard to stir
• An indifferent philosopher
• Unruffled