Letters 64.8

But even if the old masters have discovered everything, one thing will be always new,—the application and the scientific study and classification of the discoveries made by others. Assume that prescriptions have been handed down to us for the healing of the eyes; there is no need of my searching for others in addition; but for all that, these prescriptions must be adapted to the particular disease and to the particular stage of the disease. Use this prescription to relieve granulation of the eyelids, that to reduce the swelling of the lids, this to prevent sudden pain or a rush of tears, that to sharpen the vision. Then compound these several prescriptions, watch for the right time of their application, and apply the proper treatment in each case.

The cures for the spirit also have been discovered by the ancients; but it is our task to learn the method and the time of treatment.

Seneca, Letters to Lucilius 64.8, translated by Richard Mott Gummere