William Peter Blatty

God never talks. But the devil keeps advertising, Father. The devil does a lot of commercials.

Perhaps evil is the crucible of goodness... and perhaps even Satan - Satan, in spite of himself - somehow serves to work out the will of God.

We mourn the blossoms of May because they are to whither; but we know that May is one day to have its revenge upon November, by the revolution of that solemn circle which never stops---which teaches us in our height of hope, ever to be sober, and in our depth of desolation, never to despair.

The demon is a liar. He will lie to confuse us; but he will also mix lies with the truth to attack us. His attack is psychological, Damien. And powerful.

Yet I think the demon's target is not the possessed; it is us . . . the observers . . . every person in this house. And I think---I think the point is to make us despair; to reject our own humanity, Damien: to see ourselves as ultimately bestial; as ultimately vile and putrescent; without dignity; ugly; unworthy.

You don't blame us for being here, do you? After all, we have no place to go. No home... Incidentally, what an excellent day for an exorcism...