Mr. Prud'homme, a substitute teacher during the summer session, comes to the dormitory to talk to Finny and Gene about them not coming to dinner the night before. Mr. Prud'homme is
"broad-shouldered, grave, and he (wears) a gray business suit...he enforce(s) such rules as he (knows); missing dinner (is) one of them."
Mr. Prud'homme's attempt to enforce the rule about dinner is half-hearted at best; it can hardly be called a reprimand. When asked why he and Gene had been absent, Finny immediately launches into a lengthy and reasonable explanation, telling the Master that they
"had been swimming in the river...then there had been a wrestling match, then there was that sunset that anybody would want to watch, then there'd been several friends (they) had to see on business..."
When Mr. Prud'homme breaks in to point out that the boys have already missed "nine meals in the last two weeks," Finny presses his advantage, responding that
"the real reason...was that (they) just had to jump out of that tree...because (they were) all getting ready for the war."
His cursory attempt at sternness deflated, Mr. Prud'homme can do nothing more than laugh at Finny's earnest eloquence. Finny's victory of sorts is testimony to two central themes in the book - the laid-back atmosphere of the summer session as it represents the innocence of youth, and the charismatic power of Phineas (Chapter 2).