I answer that, As stated above (Article [1]), spiritual perfection was becoming to the human nature which Christ took, which perfection He attained not by making progress, but by receiving it from the very first. Now ultimate perfection does not consist in power or habit, but in operation; wherefore it is said (De Anima ii, text. 5) that operation is a "second act." We must, therefore, say that in the first instant of His conception Christ had that operation of the soul which can be had in an instant. And such is the operation of the will and intellect, in which the use of free-will consists. For the operation of the intellect and will is sudden and instantaneous, much more, indeed, than corporeal vision; inasmuch as to understand, to will, and to feel, are not movements that may be described as "acts of an imperfect being," which attains perfection successively, but are "the acts of an already perfect being," as is said, De Anima iii, text. 28. We must therefore say that Christ had the use of free-will in the first instant of His conception.