In note [4.29b] a somewhat different interpretation is offered according to more modern views of this important passage. St Thomas and the older school take the emptying (exinanitio, kenôsis) to consist in the Incarnation itself. The more modern view represents it as consisting, not in the Incarnation itself, but in the manner of life chosen by the Word Incarnate, a life fraught with the miseries, needs and liabilities of ordinary humanity, whereas the glory and impassibility, which He assumed only at His resurrection, was His by right from His mother's womb. This is the meaning of that term, so celebrated in modern theology, kenosis. If we regard the divine nature, the Incarnation itself was, as St Thomas says, "no loss of God's own greatness," which nothing can possibly diminish. Again, if we regard the human nature assumed at the Incarnation, that humanity, again to employ St Thomas's words, "was not emptied, but exalted," -- and that much more by the hypostatic union than by any Nestorian inhabitatio divinitatis. Either way explained, the passage tells against Nestorius.
Of God and His Creatures: 4.34