The stoics, the academic sceptics and the epicureans all to various degrees basically agreed—or at least largely lived as if they agreed—that happiness was ataraxia, imperturbable calm and tranquility. This is a useful and important corrective to our busy work and busy “leisure”. But at the sme time, it’s really a quite empty and negative picture of life’s fulfillment. It’s more like a picture of how to get done with life without too much misery.
Perhaps they had a part of the truth: perhaps what is truly worth having is imperturbably, calmly and tranquilly doing certain things, such as enjoying the companionship of those we love—God above all. But the ataraxia is just a mode of the worthwhile activity rather than the center of it.
Furthermore, perhaps these ancients were extensionally right: for perhaps the only way to have ataraxia is by being with God, since our hearts are restless apart from him. In that case, ataraxia isn’t happiness, or worth pursuing for its own sake, but is a sign of happiness.