This need comes from the will's punishment, not its nature
Thesis LXVII. That author is careful to point out that this need of heavenly delight for willing and acting, and the weakness of our will that makes it unable to be moved to the good unless something has delighted it, or to choose between two delightful things anything other than the one that has prevailed by delighting, comes not from the essence and nature of the will but from its punishment.
He does not think that the nature of the human will, considered in itself, is such that it cannot freely pursue a good object unless that object has first delighted it. Still less does he think it necessary that, when a good object is seen, the will be touched with some delight.
Latin
LXVII. Caeterum hanc delectationis coelestis necessitatem ad volendum atque operandum, & voluntatis nostrae infirmitatem, qua fit, ut nec moveri ad bonum possit, nisi quid delectaverit, nec inter duo quae delectant aliud eligere, quam quod delectando superaverit, sedulo monet author ille, non ex essentia & natura voluntatis, sed ex ejus poena proficisci. Nec enim putat hanc esse naturam humanae voluntatis absolute consideratae, ut non possit libere bonum objectum prosequi, nisi prius delectaverit: ac multo minus existimat necessarium esse, ut viso objecto bono, voluntas tangatur aliqua delectatione.