“The Tree of Knowledge” was originally published and collected in The Soft Side (1900). It is currently most readily available in Henry James: Complete Stories 1898–1910 (Library of America).

Henry James's short story, “The Tree of Knowledge,” might have been more literally and less sacredly titled “The Bush of Belief.” At the center of the pleasant little paradise, which seems to be sculptor Morgan Mallow's life, stands that artist's complacent certainty about his genius, a confidence which he has faithfully sustained through a productive although unheralded life. Mallow's entourage is as small as his fame is restricted, and consists of a wife so devoted she receives no other name than Missus, their only off spring, Lancelot, and finally this son's godfather, Peter Brench, a literary figure we have learned to call “the friend of the family,” and a man who counts among his numerous discretions (including a prolonged though muted adoration of Mrs. Mallow) his refusal to publish his own literary endeavors.

These players form a box—the boundaries of a garden, if you like—of the most traditional kind: husband, wife, son, friend of the family. The dynamics of their relationships are determined by a diagonal that triangulates the box so that sometimes we are dealing solely with the family trio, while at other times with the romantic triangle of friend, wife, husband. The tale is itself of the simplest. Each individual, in ignorance of the true convictions of the others, is endeavoring to maintain the group's belief in the genius of its center—its grand master—and therefore each member's reason for being. A comedy of errors ensues and epiphanies abound.

The story is told from Peter Brench's point of view, and therefore is in the service of this careful man's proudly held convictions, some of which are stated early and openly while others emerge with some shyness: (first) that he has managed to maintain his friendship with Morgan Mallow while never for a moment compromising the principles of his taste by lying or deception, not easy since (second) Brench considers Mallow to be a charming man but, as an artist, a shallow pretentious hack; (third) that Mrs. Mallow's allegiance to Morgan Mallow's genius is the basis of her love for him;