Secondly, it is again evident if we consider the specific nature of Happiness.  For it has been shown above (Q. 3, A. 8) that man’s perfect Happiness consists in the vision of the Divine Essence.  Now it is impossible for anyone seeing the Divine Essence, to wish not to see It.  Because every good that one possesses and yet wishes to be without, is either insufficient, something more sufficing being desired in its stead; or else has some inconvenience attached to it, by reason of which it becomes wearisome.  But the vision of the Divine Essence fills the soul with all good things, since it unites it to the source of all goodness; hence it is written (Ps. 16:15):  “I shall be satisfied when Thy glory shall appear”; and (Wis. 7:11):  “All good things came to me together with her,” i.e. with the contemplation of wisdom.  In like manner neither has it any inconvenience attached to it; because it is written of the contemplation of wisdom (Wis. 8:16):  “Her conversation hath no bitterness, nor her company any tediousness.”  It is thus evident that the happy man cannot forsake Happiness of his own accord.  Moreover, neither can he lose Happiness, through God taking it away from him.  Because, since the withdrawal of Happiness is a punishment, it cannot be enforced by God, the just Judge, except for some fault; and he that sees God cannot fall into a fault, since rectitude of the will, of necessity, results from that vision as was shown above (Q. 4, A. 4).  Nor again can it be withdrawn by any other agent.  Because the mind that is united to God is raised above all other things:  and consequently no other agent can sever the mind from that union.  Therefore it seems unreasonable that as time goes on, man should pass from happiness to misery, and vice versa; because such like vicissitudes of time can only be for such things as are subject to time and movement.

Reply Obj. 1:  Happiness is consummate perfection, which excludes every defect from the happy.  And therefore whoever has happiness has it altogether unchangeably:  this is done by the Divine power, which raises man to the participation of eternity which transcends all change.

Reply Obj. 2:  The will can be directed to opposites, in things which are ordained to the end; but it is ordained, of natural necessity, to the last end.  This is evident from the fact that man is unable not to wish to be happy.

Reply Obj. 3:  Happiness has a beginning owing to the condition of the participator:  but it has no end by reason of the condition of the good, the participation of which makes man happy.  Hence the beginning of happiness is from one cause, its endlessness is from another. ________________________

FIFTH ARTICLE [I-II, Q. 5, Art. 5]

Whether Man Can Attain Happiness by His Natural Powers?

Objection 1:  It would seem that man can attain Happiness by his natural powers.  For nature does not fail in necessary things.  But nothing is so necessary to man as that by which he attains the last end.  Therefore this is not lacking to human nature.  Therefore man can attain Happiness by his natural powers.