Sufficient means enough to act, if one wills
Thesis CXIX. He repeats and confirms this doctrine in his Idea of speculative theology, book 4, chapter 7, where his second resolution reads: 'Only that grace is called absolutely and truly sufficient for some operation which is enough not merely for a person to be said to be able to act in some fashion, but also for him actually to act, if he chooses.'
He says he lays this down against the authors of physical predetermination. They hold that an aid is truly sufficient for operation if it gives the ability to act, even though another aid, really distinct from the sufficient one, is necessarily required for anyone actually to act. For, to take an example, a person is said to have sufficient and proximate power to see only because he has everything needed to see in fact, if he wants to see.
Latin
CXIX. Quam Doctrinam repetit & confirmat in Idea Theologiae speculativae libro quarto cap. 7. Ubi haec est ejus Resolutio 2. Ea tantum gratia dicitur absolute, & vere sufficiens ad aliquam operationem, quae sufficit non tantum ut homo dicatur utcunque posse operari, sed etiam ut actu operetur, si velit. Quod dicit se statuere contra authores Physicae praedeterminationis, qui volunt auxilium illud esse vere sufficiens ad operationem, quod tribuit posse operari, etsi necessario requiratur aliud auxilium realiter a sufficienti distinctum, ut quis actu operetur. Nec enim, exempli causa, hominem aliter dici habere sufficientem & proximam potestatem ad videndum, nisi quia habet quicquid requiritur ut actu videat, si videre velit.