Seneca, Moral Epistles 16.3
“Check yourself. Examine and consider yourself in different ways. Look at this before everything else: have you advanced in philosophy or in life itself?
Philosophy is not some illusion for the public, not a thing prepared to show off. It consists not of words but in the way things are. It is not practiced to while away the day with some distraction or to free our leisure of boredom. It shapes and builds the mind; it re-orders life; it rules our actions; it indicates what we should do and not do; it sits at the rudder and guides our journey through uncertain weather.
No one can live bravely, no one can live safely without it. In each and every hour countless things happen that need counsel. This counsel must be found in philosophy.”
Excute te et varie scrutare et observa; illud ante omnia vide, utrum in philosophia an in ipsa vita profeceris. Non est philosophia populare artificium nec ostentationi paratum. Non in verbis, sed in rebus est. Nec in hoc adhibetur, ut cum aliqua oblectatione consumatur dies, ut dematur otio nausia. Animum format et fabricat, vitam disponit, actiones regit, agenda et omittenda demonstrat, sedet ad gubernaculum et per ancipitia fluctuantium derigit cursum. Sine hac nemo intrepide potest vivere, nemo secure. Innumerabilia accidunt singulis horis, quae consilium exigant, quod ab hac petendum est.