"the language of the instrumentum signifies no limitation of human flourishing or freedom (liberum arbitrium), but rather the action of God in Christ fulfills and realizes the integrity of 'an instrument animated by a rational soul,' such that being the instrumentum Divinitatis ensures that in this human being, human nature and freedom flourish to the fullest extent. In other words, the divine action of the Logos in the humanity of Christ is noncompetitive with the action of his human nature; it is acted upon so as to act (ita agit quod etiam agitur)—that is, to be reduced to act and so flourish at the highest pitch of integral human activity. This means that the more God acts in the human nature of Christ, the more this humanity in turn realizes an action that is integrally human."
Aaron Riches, "Theandric humanism: Constantinople III in the thought of St. Thomas Aquinas," Pro ecclesia 23, no. 2 (Spring 2014): 203-204 (195-218). Old hat, of course. But it's always nice to see this acknowledged. And this one occurs in the context of a discussion of Gethsemane and the cross, such that "the most fundamental aspect of willing in Christ involves drawing into divine unio every natural inclination of the fallen state through the liberum arbitrium of human ascent now perfectly united with the 'I' of the divine Son" (203, underscoring mine) "'in Christ's peculiar state as both comprehensor and wayfarer'" (Corey L. Barnes, as quoted on p. 210). Cf. this entry.