Letters 121.5

Meanwhile, allow me to discuss thoroughly some points which may seem now to be rather remote from the present inquiry. We were once debating whether all animals had any feelings about their “constitution.” That this is the case is proved particularly by their making motions of such fitness and nimbleness that they seem to be trained for the purpose. Every being is clever in its own line. The skilled workman handles his tools with an ease born of experience; the pilot knows how to steer his ship skilfully; the artist can quickly lay on the colours which he has prepared in great variety for the purpose of rendering the likeness, and passes with ready eye and hand from palette to canvas. In the same way an animal is agile in all that pertains to the use of its body.

Seneca, Letters to Lucilius 121.5, translated by Richard Mott Gummere