Doubt VI: Whether the sixth beatitude, Blessed are the clean of heart, corresponds to the gift of understanding

St. Bonav. de 7. donis, cap. 3. and St. Th. here, together with St. August. lib. 1. de serm. Domini in monte, cap. 9., assert that it does.

It is proved from the Seraphic Doctor, cap. 4. de dono Intellectus. As the light of the sun is related to the seeing of sensible things, and to the purifying of the air, so is Understanding related to the vision of spiritual things; but the cleanness of the air arises from the solar light, so that the Sun itself is clearly seen, and in the absence of this light the air is darkened, and as it were sullied: Therefore. To this the holy Doctor adduces that Psalm 81: They have not known nor understood, they walk on in darkness, where the cause of the soul's being darkened is referred back to a defect of Understanding. Then the holy Doctor assigns three degrees of the cleanness of heart, which are as it were the morning, the midday, and the evening of Understanding.

The first degree is when, through the Gift of Understanding, being recalled to our interior self, with the light of compunction we wipe away all the stains and darknesses of sins, and there shines upon us a certain twilight of divine light, whence may arise the morning cleanness of heart, which corresponds to the morning of understanding.

The second degree is a certain excess of light and fervor of heart, penetrating all the veils that overshadow the rays of truth, illuminating, strengthening(?) and inflaming the mind with clarity and at the same time with charity: And hence is born the midday of Understanding, and the midday cleanness of heart.

The third degree is when this fervent clarity declines toward evening, the Lord nevertheless remaining as the fount of all clarity and fervor; Hence at once the sleep of contemplation is begun, and the nocturnal delights are celebrated, with the lamps of divine splendor lit on every side; see the Seraphic Doctor himself, saying marvelous things about these, beyond human understanding, through several chapters.