How we reason ourselves into wrong (CM Vol 6 Quote for the Day)

"He shall be Thane of Cawdor, and, behold, confirmation arrives on the spot. He shall also be king. Well, if this is decreed, what can he do? He is no longer a free agent. And a score of valid arguments unfold themselves showing how Scotland, the world, his wife, himself, would be enhanced, would flourish and be blessed if he had the opportunity to do what was in him. Opportunity? The thing was decreed! It rested with him to find the means, the tools. He was not without imagination, had a poetic mind and shrank before the horrors he vaguely foresaw. But reason came to his aid and step by step the whole bloody tragedy was wrought out before his prescient mind." ~~ Charlotte Mason, "The Way of the Reason" (Towards a Philosophy of Education)