De Culpis Domi Petendis
Therefore, watch heedfully the Fault of another, that thou mayst correct it in thyself. For if it were not in thee, thou couldst not perceive it or understand it. Lo, in thine Ecstasy of Love, thou callest upon the Universe to bear Witness that to this End alone was it created; it is unthinkable that thou shouldst love another, and incomprehensible that any Man should grieve. Yet ere the Moon change her Quarter, thou art free of thy Lunes, and lovest another, and it may be grievest in thyself while he that amazed thee hath joined the Company of the Rejoicing. Watch then, and heed thyself; and pay no Heed to thy Fellows, insofar as they impede thee not. And let this be the Rule. For every Will is pure and every Orbit free; but Error bringeth Confusion. See therefore that none leave his Path, lest he foul that of his Brother; and remember also that with Speed cometh Ease of Control. Let each Man therefore urge briskly his Chariot in a right Line toward the Centre; for two Radii cannot cross. And beware most of this Love, because it lieth so close to Will that Dis-ease thereof easily imparteth his Error to the Whole Way of the Magician.
 On Watching for Faults in the House