In the order of nature and in the order of grace, St. Augustine tells us that God alone is the author of all good in us. We cannot wish to do good or do good without Him.
Natural goodness is what those who are not baptized and try to be good have, but even this is from God.
Garrigou-Lagrange clearly refers to the teachings of the Church on this matter. Basically, the Church has accepted and made into teachings the insights of St. Augustine against the Pelagians and Semipelagians. There is Original Sin, grace is necessary and gratuitous, and we are absolutely dependent on God for all good actions and good thoughts.
From St. Augustine was formed the teaching on predilection; again, a state which demands grace from God.
St. Paul, again, is the master of theology regarding this subject, as noted in the posts below. Garrigou-Lagrange refers to him again.
"It is God who worketh in you, according to His good will. For who distinguisheth thee? Or what has thou that thou hast not received?" Phil. 2:13 and I Cor. 4:7.
The Church then, as Garrigou-Lagrange notes, clarified this position further as against the Calvinists, Bajanists, and Jansenists.
Also, there is an entire series of councils earlier than these heresies which addressed the teaching, on page 18 of the book here examined.
One of the most important points clarified early on was that God does not predestine anyone to evil. There is no such thing as destiny or fate to become evil. The Church has always held up the primacy of free will in man to choose. That God permits evil is a mystery.
Here is a quotation from the Council of Quierzy:
"Our will, aided by prevenient grace and concomitant is free to do what is good; and our will, forsaken by grace, is free to do what is evil."
Sin happens with God's permission because of justice.
Again, another quotation from the above council: "Almighty God will without exception, all men to be saved, however, it is the gift of Him who saves; if some perish, it is the fault of them that perish."
There is no predestination to evil; God want all men to be saved and gives to all the graces necessary for salvation. But, free will is also a gift.
All sin is committed with His foreknowledge and permission. This is a hard statement for some people. But, as one who has sinned seriously, I can state that the sin led me back to God in a more realistic and humble way. That God allowed sin in my life makes me realize His great mercy and my freedom.
To be continued....