Seeming more of an ideal than a real character, the nearly perfect Phineas, whose one name conjures the mythological, arouses the immediate suspicion of the all too human Gene Forrester. Phineas is a natural: his athletic ability is so superior that he accomplishes feats with little effort and without assigning any magnitude to his accomplishments. For instance, he breaks the school swimming record without out having a witness to record it. His innocence is such that his acts of breaking rules are ignored by the headmasters because they are done in the "Blythe spirit" of idealized and spontaneous youth. In Chapter 1 Gene remarks,
He got away with everything because of the extraordinary kind of person he was.
In addition, he is warm and without any pettiness, trusting in people because he himself can be trusted. When, for example, he considers that Gene may have knocked him from the limb, he is ashamed of even thinking that Gene is responsible, telling Gene in Chapter 5, "I'm sorry about that feeling I had."
It is the qualities of lack of pretence and innocence in Phineas that Gene recalls as he returns to Devon School in order to claim his "separate peace" and come to the recognition that it has been something "ignorant in the human heart" which made him envious of Finny; something of which he was jealous that made him wish to outdo Finny.
Phineas is the quintessential youth of nature. Completely incapable of jealousy or envy, Finny responds to the moment with ingenuousness and natural emotions. He is almost like a mythological god of frolic and youth, denying the entrance of war and hatred and other human foibles into his heart, for when these evils do enter his being, these human foibles are fatal to him:
He shook his head sharply, closing his eyes, and then he turned to regard me with a handsome mask of face. "I just don't care. Never mind," and he started across the marble floor toward the doors.
...."You get all your facts!" I had never seen Finny crying...Then these separate sounds collided into the general tumult of his body falling clumsily down the white marble stairs.
Clearly, Phineas represents the good that man could be without the fears of human nature that drive it to commit evil. In the conclusion, Gene narrates,
Only Phineas never was afraid, only Phineas never hated anyone. Other people experienced this fearful shock somewhere, this sighting of the enemy, and so began an obsessive labor or defense....construct[ing] at infinite cost to themselves these Maginot Lines....
Phineas is good because he does not allow the ugliness of human nature, its great fears which give birth to jealousy and envy, to enter his being.