Letters 116.4

And if you cry: “One should be allowed a certain amount of grieving, and a certain amount of fear,” I reply that the “certain amount” can be too long-drawn-out, and that it will refuse to stop short when you so desire. The wise man can safely control himself without becoming over-anxious; he can halt his tears and his pleasures at will; but in our case, because it is not easy to retrace our steps, it is best not to push ahead at all.

Seneca, Letters to Lucilius 116.4, translated by Richard Mott Gummere