But this house stands by four corners for this reason, that the firm fabric of our mind is upheld by Prudence, Temperance, Fortitude, Justice. This house is grounded on four corners, in that the whole structure of good practice is raised in these four virtues. And hence do four rivers of Paradise water the earth. For while the heart is watered with these four virtues, it is cooled from all the heat of carnal desires. Yet sometimes when idleness steals on the mind, prudence waxes cold; for when it is weary and turns slothful, it neglects to forecast coming events. Sometimes while some delight is stealing on the mind, our temperance decays. For in whatever degree we are led to take delight in the things of this life, we are the less temperate to forbear in things forbidden. Sometimes fear works its way into the heart and confounds the powers of our fortitude, and we prove the less able to encounter adversity, the more excessively we love some things that we dread to part with. And sometimes self-love invades the mind, makes it swerve by a secret declension from the straight line of justice: and in the degree that it refuses to refer itself wholly to its Maker, it goes contrary to the claims of justice. Thus ‘a strong wind smites the four corners of the house,’ in that strong temptation, by hidden impulses, shakes the four virtues; and the corners being smitten, the house is as it were uprooted; in that when the virtues are beaten, the conscience is brought to trouble.Gregory the Great, Moralia in Job, Book II, Section 76.