Pleasure, I have said, is to power,
as certainty to knowledge. But
perhaps it is not mere pleasure
that we seek; perhaps it is felicity.

To see the truth and be sure.
To do good and be happy.

Certainty is the end of epistemology, its goal. (If we were always and easily sure there would be no need for epistemology.)

Felicity is the end of ethics, its goal. (Happiness is the highest good and if it were easy there would be no need for ethics.)