Sonnet from a Letter, by John Keats

O thou whose face hath felt the Winter's wind,
Whose eye has seen the snow-clouds hung in mist
And the black elm tops 'mong the freezing stars,
To thee the spring will be a harvest-time.
O thou, whose only book has been the light
Of supreme darkness which thou feddest on
Night after night when Phoebus was away,
To thee the Spring shall be a triple morn.
O fret not after knowledge- I have none,
And yet my song comes native with the warmth.
O fret not after knowledge- I have none,
And yet the Evening listens. He who saddens
At thought of idleness cannot be idle,
And he's awake who thinks himself asleep.

c. 1818

One of the best poems ever on the Via Negativa.