Augustine on Free Will and Irresistible Grace

"Who am I, and what am I? What evil has not been in my deeds, or if not in my deeds, my words, or if not in my words, my will? But You, Lord, are good and merciful, and Your right hand has respected the depth of my death and, from the bottom of my heart, has emptied that abyss of corruption. And Your whole gift to me was not to will what I willed, and to will what You willed. But where was my free will through all those years, and out of what low and deep recess was my free will called forth in a moment so I could submit my neck to Your easy yoke, and my shoulders to Your light burden, Christ Jesus, my Helper and my Redeemer? How sweet it suddenly became to me, to lack the "sweetness" of those follies, and what I was afraid to be separated from was now a joy to part with! You cast them forth from me, You who are the true and highest sweetness. You cast them forth and entered in their place Yourself, You who are sweeter than all pleasure, though not to flesh and blood, brighter than all light, but more hidden than all depths, higher than all honor, but not to the lofty in their own conceits. Now my soul was free from the biting cares of seeking and getting, weltering in filth, and scratching off the itch of lust. And my infant tongue spoke freely to You, my brightness and my riches and my health, Lord my God."

The Confessions of Saint Augustine, published by Whitaker House, 1996, pp. 213-214 (emphasis mine)

Here Augustine describes his conversion in terms that reveal his firm belief in total depravity. He views his own sinfulness as an evil nature resulting in a bondage of the will. He recognizes that his faith was initiated by God's effectual calling rather than his own free will, which was trapped in a "low and deep recess" prior to the divine call. He posits a paradoxical "free will" which is limited by the boundaries of the sinful nature and in need of awakening by God's grace. And because of these things, Augustine gives all the glory to God.