Letters 93.9

And yet how long are we to keep living? We have had the joy of learning the truth about the universe. We know from what beginnings Nature arises; how she orders the course of the heavens; by what successive changes she summons back the year; how she has brought to an end all things that ever have been, and has established herself as the only end of her own being. We know that the stars move by their own motion, and that nothing except the earth stands still, while all the other bodies run on with uninterrupted swiftness. We know how the moon outstrips the sun; why it is that the slower leaves the swifter behind; in what manner she receives her light, or loses it again; what brings on the night, and what brings back the day. To that place you must go where you are to have a closer view of all these things.

Seneca, Letters to Lucilius 93.9, translated by Richard Mott Gummere