In Chapter 2, there is "...the clean-washed shine of summer mornings..." (21), a metaphor that suggests that summer is something that is washed and polished. In Chapter 4, Gene says, "Summer lazed on" (55), as though it were a person who could "laze." In addition to those quotes, it is possible to look at the book's title as a kind of metaphor. The "separate peace" is the summer before these students must go off to war. So summer is a kind of metaphor, for the calm before the storm, the peace before the war, and the last stage of childhood before one must grow up. For most of us, summer is a kind of metaphor for carefree childhood, don't you think?