Epistle LXXII. On business as the enemy of philosophy
For there is never a moment when fresh employments will not come along; we sow them, and for this reason several spring up from one. Then, too, we keep adjourning our own cases, saying “as soon as I am done with this, I shall settle down to hard work,” or: “If I ever set this troublesome matter in order, I shall devote myself to study”
But the study of philosophy is not to be postponed until you have leisure; everything else is to be neglected in order that we may attend to philosophy, for no amount of time is long enough for it… We must resist the affairs which occupy our time; they must not be untangled, but rather put out of the way. Indeed, there is no time that is unsuitable for helpful studies; and yet many a man fails to study amid the very circumstances which make study necessary.
Seneca Epistles 66-92, Translation by Richard Gummere. Loeb Classical Library.