text: This very thing, my dear Lucilius, is, I believe, exactly what a great-souled man ought not to do; his influence is weakened; it has too little effect upon those whom it might have set right if it had not grown so stale. The archer ought not to hit the mark only sometimes; he ought to miss it only sometimes. That which takes effect by chance is not an art. Now wisdom is an art; it should have a definite aim, choosing only those who will make progress, but withdrawing from those whom it has come to regard as hopeless, – yet not abandoning them too soon, and just when the case is becoming hopeless trying drastic remedies.