Works of St. Anselm, tr. by Sidney Norton Deane, [1903], at sacred-texts.com
How all the ways of God are compassion and truth; and yet God is just in all his ways. ‑‑We cannot comprehend why, of the wicked, he saves these rather than those, through his supreme goodness: and condemns those rather than these, through his supreme justice.
BUT, is there any reason why it is not also just, according to thy nature, O Lord, that thou shouldst punish the wicked? Surely it is just that thou shouldst be so just that thou canst not be conceived more just; and this thou wouldst in no wise be if thou didst only render goods to the good, and not evils to the evil. For, he who requiteth both good and evil according to their deserts is more just than he who so requites the good alone. It is, therefore, just, according to thy nature, O just and gracious God, both when thou dost punish and when thou sparest.
Truly, then, all the paths of the Lord are mercy and truth (Psalms 25:10); and yet the Lord is righteous in all his ways (Psalms 145:17). And assuredly without inconsistency: For, it is not just that those whom thou dost will to punish should be saved, and that those whom thou dost will to spare should be condemned. For that alone is just which thou dost will; and that alone unjust which thou dost not will. So, then, thy compassion is born of thy justice.
For it is just that thou shouldst be so good that thou art good in sparing also; and this may be the reason why the supremely Just can will goods for the evil. But if it can be comprehended in any way why thou canst will to save the wicked, yet by no consideration can we comprehend why, of those who are p. 18 alike wicked, thou savest some rather than others, through supreme goodness; and why thou dost condemn the latter rather than the former, through supreme justice.
So, then, thou art truly sensible (sensibilis), omnipotent, compassionate, and passionless, as thou art living, wise, good, blessed, eternal: and whatever it is better to be than not to be.