Reply Obj. 1: If the good tree be taken to signify the good will, it must be in so far as the will derives goodness from the act willed and from the end intended.
Reply Obj. 2: A man sins by his will, not only when he wills an evil end; but also when he wills an evil act.
Reply Obj. 3: Voluntariness applies not only to the interior act of the will, but also to external actions, inasmuch as they proceed from the will and the reason. Consequently the difference of good and evil is applicable to both the interior and external act. ________________________
THIRD ARTICLE [I-II, Q. 20, Art. 3]
Whether the Goodness and Malice of the External Action Are the Same
As Those of the Interior Act?
Objection 1: It would seem that the goodness and malice of the interior act of the will are not the same as those of the external action. For the principle of the interior act is the interior apprehensive or appetitive power of the soul; whereas the principle of the external action is the power that accomplishes the movement. Now where the principles of action are different, the actions themselves are different. Moreover, it is the action which is the subject of goodness or malice: and the same accident cannot be in different subjects. Therefore the goodness of the interior act cannot be the same as that of the external action.
Obj. 2: Further, "A virtue makes that, which has it, good, and renders its action good also" (Ethic. ii, 6). But the intellective virtue in the commanding power is distinct from the moral virtue in the power commanded, as is declared in Ethic. i, 13. Therefore the goodness of the interior act, which belongs to the commanding power, is distinct from the goodness of the external action, which belongs to the power commanded.
Obj. 3: Further, the same thing cannot be cause and effect; since nothing is its own cause. But the goodness of the interior act is the cause of the goodness of the external action, or vice versa, as stated above (AA. 1, 2). Therefore it is not the same goodness in each.
On the contrary, It was shown above (Q. 18, A. 6) that the act of the will is the form, as it were, of the external action. Now that which results from the material and formal element is one thing. Therefore there is but one goodness of the internal and external act.
I answer that, As stated above (Q. 17, A. 4), the interior act of the will, and the external action, considered morally, are one act. Now it happens sometimes that one and the same individual act has several aspects of goodness or malice, and sometimes that it has but one. Hence we must say that sometimes the goodness or malice of the interior act is the same as that of the external action, and sometimes not. For as we have already said (AA. 1, 2), these two goodnesses or malices, of the internal and external acts, are ordained to one another. Now it may happen, in things that are subordinate to something else, that a thing is good merely from being subordinate; thus a bitter draught is good merely because it procures health. Wherefore there are not two goodnesses, one the goodness of health, and the other the goodness of the draught; but one and the same. On the other hand it happens sometimes that that which is subordinate to something else, has some aspect of goodness in itself, besides the fact of its being subordinate to some other good: thus a palatable medicine can be considered in the light of a pleasurable good, besides being conducive to health.