Seneca · On real ethics as superior to syllogistic subtleties
Letters 117.4
Let me tell you what answers other philosophers make to these objectors, before I myself begin to form my own creed and to take my place entirely on another side. “Judged in that light,” they say, “not even living happily is a Good. Willy nilly, such persons ought to reply that the happy life is a Good, but that living happily is not a Good.”
Seneca, Letters to Lucilius 117.4, translated by Richard Mott Gummere