Why did Mr. Benedict ask Reynie to remember the White Knight?

Mr. Benedict asked Reynie to remember the White Knight to encourage him not to doubt his abilities during a challenging test. The character of the White Knight symbolizes courage, resilience, and the idea of facing difficulties head-on. In the context of the story, Reynie faces numerous challenges, and this reminder serves as a motivational tool to boost his confidence. By invoking the image of the White Knight, Mr. Benedict is reinforcing the notion that Reynie possesses the strength and intelligence to overcome obstacles. This encouragement is key during moments of self-doubt, which Reynie experiences throughout the narrative, making it essential for him to maintain faith in his skills.