Seneca, Moral Epistle 98
“Therefore I do not suggest that you be indifferent. Rather, you should avoid whatever makes you fear. Whatever can be anticipated through planning, anticipate. Whatever would do you harm, spot it and avoid it long before it happens. In this, confidence and a mind hardened enough to tolerate everything will bring you the greatest aid. Whoever can endure fortune, can also beware of it. Certainly, there are no rolling waves on tranquil waters. Nothing is more pitiful or foolish than fearing things ahead of time! What is this insanity in anticipating your troubles!
Finally, to summarize briefly what I believe and to outline for you those troublemakers and self-abusers—for they are as intemperate in their misfortunes as they were before them. The person suffers more than is needed who suffers before it is needed. This kind of a person does not put his sorrow in perspective for the same reason he does not expect it—because of the same intemperance he imagines that his own happiness will last forever and that whatever he encounters will continue to improve as long as they last. Forgetful of the balance upon which all human affairs are chanced, one safeguards for himself only the consistency of chance.”
Nec ideo praecipio tibi neglegentiam. Tu vero metuenda declina. Quidquid consilio prospici potest, prospice. Quodcumque laesurum est, multo ante quam accidat, speculare et averte. In hoc ipsum tibi plurimum conferet fiducia et ad tolerandum omne obfirmata mens. Potest fortunam cavere, qui potest ferre. Certe in tranquillo non tumultuatur. Nihil est nec miserius nec stultius quam praetimere. Quae ista dementia est malum suum antecedere? Denique ut breviter includam quod sentio, et istos satagios ac sibi molestos describam tibi, tam intemperantes in ipsis miseriis quam sunt ante illas. Plus dolet quam necesse est, qui ante dolet quam necesse est; eadem enim infirmitate dolorem non aestimat, qua non exspectat; eadem intemperantia fingit sibi perpetuam felicitatem suam, fingit crescere debere quaecumque contigerunt, non tantum durare; et oblitus huius petauri, quo humana iactantur, sibi uni fortuitorum constantiam spondet.