Thomas Aquinas,
Summa Theologiae — Question 15 - OF THE DEFECTS OF SOUL ASSUMED BY CHRIST…
“ There is no reason why a thing may not of itself be contrary to the will, and yet be willed by reason of the end, to which it is ordained, as bitter medicine is not of itself desired, but only as it is ordained to health. And thus Christ's death and passion were of themselves involuntary, and caused sorrow, although they were voluntary as ordained to the end, which is the redemption of the human race. ”
