Hence we must say that for the knowledge of any truth whatsoever man needs Divine help, that the intellect may be moved by God to its act.  But he does not need a new light added to his natural light, in order to know the truth in all things, but only in some that surpass his natural knowledge.  And yet at times God miraculously instructs some by His grace in things that can be known by natural reason, even as He sometimes brings about miraculously what nature can do.

Reply Obj. 1:  Every truth by whomsoever spoken is from the Holy Ghost as bestowing the natural light, and moving us to understand and speak the truth, but not as dwelling in us by sanctifying grace, or as bestowing any habitual gift superadded to nature.  For this only takes place with regard to certain truths that are known and spoken, and especially in regard to such as pertain to faith, of which the Apostle speaks.

Reply Obj. 2:  The material sun sheds its light outside us; but the intelligible Sun, Who is God, shines within us.  Hence the natural light bestowed upon the soul is God’s enlightenment, whereby we are enlightened to see what pertains to natural knowledge; and for this there is required no further knowledge, but only for such things as surpass natural knowledge.

Reply Obj. 3:  We always need God’s help for every thought, inasmuch as He moves the understanding to act; for actually to understand anything is to think, as is clear from Augustine (De Trin. xiv, 7). ________________________

SECOND ARTICLE [I-II, Q. 109, Art. 2]

Whether Man Can Wish or Do Any Good Without Grace?

Objection 1:  It would seem that man can wish and do good without grace.  For that is in man’s power, whereof he is master.  Now man is master of his acts, and especially of his willing, as stated above (Q. 1, A. 1; Q. 13, A. 6).  Hence man, of himself, can wish and do good without the help of grace.

Obj. 2:  Further, man has more power over what is according to his nature than over what is beyond his nature.  Now sin is against his nature, as Damascene says (De Fide Orth. ii, 30); whereas deeds of virtue are according to his nature, as stated above (Q. 71, A. 1).  Therefore since man can sin of himself he can wish and do good.

Obj. 3:  Further, the understanding’s good is truth, as the Philosopher says (Ethic. vi, 2).  Now the intellect can of itself know truth, even as every other thing can work its own operation of itself.  Therefore, much more can man, of himself, do and wish good.

On the contrary, The Apostle says (Rom. 9:16):  “It is not of him that willeth,” namely, to will, “nor of him that runneth,” namely to run, “but of God that showeth mercy.”  And Augustine says (De Corrept. et Gratia ii) that “without grace men do nothing good when they either think or wish or love or act.”