Without contraries there is no progression.

When I tell the truth, it is not for the sake of convincing those who do not know it, but for the sake of defending those that do.

And priests in black gowns were walking their rounds and binding with briars my joys and desires. (from 'The Garden of Love')

Can I see another's woe, and not be in sorrow too? Can I see another's grief, and not seek for kind relief?

Work up imagination to the state of vision.

The apple tree never asks the beech how he shall grow, nor the lion, the horse, how he shall take his prey.

Think in the morning. Act in the noon. Eat in the evening. Sleep in the night.