. . .Mercy is especially to be attributed to God, as seen in its effect, but not as an affection of passion. In proof of which it must be considered that a person is said to be merciful [misericors], as being, so to speak, sorrowful at heart [miserum cor]; being affected with sorrow at the misery of another as though it were his own. Hence it follows that he endeavors to dispel the misery of this other, as if it were his; and this is the effect of mercy. To sorrow, therefore, over the misery of others belongs not to God; but it does most properly belong to Him to dispel that misery, whatever be the defect we call by that name. . . . Summa Theologica, Question 21, article 3.