I answer that, As is evident from what has been said above (Articles [3],5), the will tends to its object, according as it is proposed by the reason. Now a thing may be considered in various ways by the reason, so as to appear good from one point of view, and not good from another point of view. And therefore if a man's will wills a thing to be, according as it appears to be good, his will is good: and the will of another man, who wills that thing not to be, according as it appears evil, is also good. Thus a judge has a good will, in willing a thief to be put to death, because this is just: while the will of another---e.g. the thief's wife or son, who wishes him not to be put to death, inasmuch as killing is a natural evil, is also good.
Now since the will follows the apprehension of the reason or intellect; the more universal the aspect of the apprehended good, the more universal the good to which the will tends. This is evident in the example given above: because the judge has care of the common good, which is justice, and therefore he wishes the thief's death, which has the aspect of good in relation to the common estate; whereas the thief's wife has to consider the private, the good of the family, and from this point of view she wishes her husband, the thief, not to be put to death. Now the good of the whole universe is that which is apprehended by God, Who is the Maker and Governor of all things: hence whatever He wills, He wills it under the aspect of the common good; this is His own Goodness, which is the good of the whole universe. On the other hand, the apprehension of a creature, according to its nature, is of some particular good, proportionate to that nature. Now a thing may happen to be good under a particular aspect, and yet not good under a universal aspect, or vice versa, as stated above. And therefore it comes to pass that a certain will is good from willing something considered under a particular aspect, which thing God wills not, under a universal aspect, and vice versa. And hence too it is, that various wills of various men can be good in respect of opposite things, for as much as, under various aspects, they wish a particular thing to be or not to be.
But a man's will is not right in willing a particular good, unless he refer it to the common good as an end: since even the natural appetite of each part is ordained to the common good of the whole. Now it is the end that supplies the formal reason, as it were, of willing whatever is directed to the end. Consequently, in order that a man will some particular good with a right will, he must will that particular good materially, and the Divine and universal good, formally. Therefore the human will is bound to be conformed to the Divine will, as to that which is willed formally, for it is bound to will the Divine and universal good; but not as to that which is willed materially, for the reason given above.
At the same time in both these respects, the human will is conformed to the Divine, in a certain degree. Because inasmuch as it is conformed to the Divine will in the common aspect of the thing willed, it is conformed thereto in the point of the last end. While, inasmuch as it is not conformed to the Divine will in the thing willed materially, it is conformed to that will considered as efficient cause; since the proper inclination consequent to nature, or to the particular apprehension of some particular thing, comes to a thing from God as its efficient cause. Hence it is customary to say that a man's will, in this respect, is conformed to the Divine will, because it wills what God wishes him to will.
There is yet another kind of conformity in respect of the formal cause, consisting in man's willing something from charity, as God wills it. And this conformity is also reduced to the formal conformity, that is in respect of the last end, which is the proper object of charity.