1a 2ae q19 a9: Whether the goodness of the will depends on its conformity to the Divine will? Yes.

Bonitas voluntatis dependet ex conformitate ad voluntatem divinam quia sicut dictum est, bonitas voluntatis dependet ex intentione finis; finis autem ultimus voluntatis humanae est summum bonum, quod est Deus, ut supra dictum est.

The goodness of the will depends on its conformity to the Divine will because, as stated above (a7), the goodness of the will depends on the intention of the end; and the last end of the human will is the Sovereign Good, namely, God, as stated above (q1 a8; q3 a1).

Voluntas hominis non potest conformari voluntati divinae per aequiparantiam, sed per imitationem. Et similiter conformatur scientia hominis scientiae divinae, inquantum cognoscit verum. Et actio hominis actioni divinae, inquantum est agenti conveniens. Et hoc per imitationem, non autem per aequiparantiam.

The human will cannot be conformed to the will of God so as to equal it, but only so as to imitate it. In like manner human knowledge is conformed to the Divine knowledge, in so far as it knows truth. And human action is conformed to the Divine, in so far as it is becoming to the agent. And this by way of imitation, not by way of equality.

Requiritur ad bonitatem humanae voluntatis, quod ordinetur ad summum bonum.

The goodness of the human will requires it to be ordained to the Sovereign Good.

Hoc autem bonum primo quidem et per se comparatur ad voluntatem divinam ut obiectum proprium eius. Illud autem quod est primum in quolibet genere, est mensura et ratio omnium quae sunt illius generis.

Now this Good is primarily and essentially referred to the Divine will, as its proper object. Again, that which is first in any class is the measure and formal aspect of all that belongs to that class.

Unumquodque autem rectum et bonum est, inquantum attingit ad propriam mensuram. Ergo ad hoc quod voluntas hominis sit bona, requiritur quod conformetur voluntati divinae.

Moreover, everything attains to rectitude and goodness, insofar as it is in accord with its proper measure. Therefore, in order that man's will be good it needs to be conformed to the Divine will.