Guide Mentor
Character Role Analysis
Dr. Trefusis
Dr. Trefusis is perfectly positioned to be Octavian's mentor. After all, he is Octavian's favorite tutor, and for good reason too—he's the one who starts schooling Octavian on the history of slavery after Octavian gets whipped for the first time. He's also the man responsible for Octavian's final escape. In short, he's the man who actually helps Octavian become, well, a man.
Mr. Gitney
All right. How can Mr. Gitney be a guide or a mentor when he willingly keeps Octavian and his mother enslaved? Yeah, he's not always that great, but before Mr. Sharpe enters the picture, Mr. Gitney is the closest thing Octavian has to a father figure. Granted, he's got some strange—even cruel—instructional methods, but he's more about tough love than cruelty for cruelty's sake. More to the point, he's the one who gives Octavian the education that Octavian—for better or worse—loves. Think of him as a mentor for Octavian's early years.
Pro Bono
Octavian's education at the College may help him think through his life, but it can't give him all the knowledge he needs to understand his status as a slave. That's why he needs Bono. Bono knows what slavery is all about, and he passes this knowledge down to Octavian, especially once Mr. Gitney falls under Mr. Sharpe's influence. Bono steps in and becomes Octavian's big brother/father figure, plus he gives Octavian the literal keys out of the Canaan house and into his brief period of freedom.