Letters 53.9

If you were ill, you would stop caring for your personal concerns, and forget your business duties; you would not think highly enough of any client to take active charge of his case during a slight abatement of your sufferings. You would try your hardest to be rid of the illness as soon as possible. What, then? Shall you not do the same thing now? Throw aside all hindrances and give up your time to getting a sound mind; for no man can attain it if he is engrossed in other matters. Philosophy wields her own authority; she appoints her own time and does not allow it to be appointed for her. She is not a thing to be followed at odd times, but a subject for daily practice; she is mistress, and she commands our attendance.

Seneca, Letters to Lucilius 53.9, translated by Richard Mott Gummere