Just as we cannot stop the movement of the heavens, revolving as they do with such speed, so we cannot restrain our thought. And then we send all the faculties of the soul after it, thinking we are lost, and have misused the time that we are spending in the presence of God. Yet the soul may perhaps be wholly united with Him in the Mansions very near His presence, while thought remains in the outskirts of the castle, suffering the assaults of a thousand wild and venomous creatures and from this suffering winning merit. So this must not upset us, and we must not abandon the struggle, as the devil tries to make us do. Most of these trials and times of unrest come from the fact that we do not understand ourselves.

Fourth Mansions, Ch. 1, trans. E. Allison Peers (1961),ISBN 0-385-03643-6 p. 77 - Interior Castle (1577)