Free Will and Forgiveness

The first sort by their own suggestion fell,
self-tempted, self-deprav'd: Man falls deceiv'd
By the other first: Man therefore shall find grace,
The other none

Here is the choice of free will cropping up again, although in a very different sense than how we normally think about it. The fallen angels (now demons) chose their fate. They, out of their own greed and weakness, decided to fall out of God's favor. Man, however, was deceived by these creatures. Although Man had a choice to chose evil over good, he still was not motivated out of his own wickedness to turn away from God.

And therein lies the difference, and the reason why Satan cannot repent, right? If he was self-tempted in Heaven, eternal Paradise, then why would he satisfied anywhere else, on Earth or elsewhere, if he wasn't The Authority?