I cannot possibly summarize the sections in Ripperger on free will, but I want to share a bit from the section on choosing evil.
The will normally chooses what is perceived as a good. But, what about people who make evil choices? Daily, we see people choosing to be violent, crass, gross, insensitive, morally evil, and they are choosing such sins.
As Ripperger points out, "The definition of love is 'willing the good of another...'"
When we will, we make an act of love.
Some people accept the evil in order to get a good. Evil, notes Ripperger, becomes part of the will if the person accepts evil as part of the willing. He adds, "People who choose evil are not OK."
The next bit is really interesting. "The second aspect of this issue is that the intellect is forced to act contrary to its very nature." The intellect knows the difference between good and evil. Therefore, if one acts against one's intellect, one is being less than human; in fact, one is being irrational.
To pursue evil is irrational, which is why sin can lead to mental illness.
Actual sin, as Father notes, is a sign that man is "not functioning according to the natural state in which he was intended to thrive."
Sin is not normal, as the world wants to make us believe. It is sub-normal.
I cannot recommend Father Ripperger's book enough. If any reader is in psychology or planning on making that a career, reading this book is a must.