St. Thomas Aquinas, Summa theologiae I.98.Resp. Cf. Jean-Pierre Torrell, O.P., "Nature et grâce chez Thomas d'Aquin," Revue thomiste 101, no. 1/2 (2001): 177 (167-202).
Which means that the "state of original justice," the phrase favored by Aquinas when discussing original sin, or "innocence," the phrase favored by Aquinas in "the treatise on the creation of the first man" (Torrell, 175), is not natural, but supernatural:
such a subjection of the body to the soul and of the lower parts to reason, was not from nature; otherwise it would have remained after sin, as Dionysius declares (Div. Nom. iv). . . . the primitive subjection by virtue of which reason was subject to God was not a merely natural gift, but a supernatural endowment of grace(Summa theologiae I.95.1.Resp., trans. FEDP; cf. Torrell, 177-178).
human nature was established in its first beginning so that the inferior powers were perfectly subject to reason, the reason to God, the body to the soul, and God was by His grace supplying what nature lacked for this arrangement(Summa contra Gentiles IV.52.6 (=Marietti no. 3880), trans. Charles J. O'Neil; cf. Torrell, 178). Thus, St. Thomas rejects "the opinion of those who think that sanctifying grace is not comprised in original justice":
Original justice included sanctifying grace (gratiam gratum faciens) and I do not believe that it is true that the first man was created with his natural powers alone (in puris naturalibus)(De malo q. 4 a.2 ad 22 (Marietti, p. 531), as reproduced at Torrell, 179, who says ad 1).
Given that original justice consists principally in the submission of the human soul to God, which cannot be firm without grace, original justice could not exist without grace(De malo q.5 a.1 ad 13 (Marietti, p. 547), as reproduced at Torrell, 179).
On pp. 174-175 Torrell reproduces In II Sent. d.30 q.1 a.1 on the distinction between human nature "according to its natural principles alone," and human nature "as it was [actually] created (instituta)", "the concrete situation of man fresh from the [(sorti des)] hands of God" (Torrell, 175).