An unnamed freelance writer living with deep disillusionment over the failed counterculture movements of the 1960s and 1970s. He works on contract for various clients but feels a lingering cynicism about human society. Despite his skepticism, a persistent urge to understand and fix the world prompts him to answer a peculiar newspaper advertisement, leading him to an empty office and a glass partition.

A highly intelligent, telepathic gorilla born in the African wild. After early years in a zoo and a traveling menagerie, he acquires human language and historical knowledge through his interactions with a wealthy benefactor. Sitting behind the glass of an empty office building, he operates as a philosophical guide, using Socratic dialogue to dismantle conventional assumptions about human history and the ecosystem.

The dominant culture of humanity that emerged during the agricultural revolution approximately 10,000 years ago. According to the philosophical framework established in the lessons, this group functions on the assumption that humans are the pinnacle of evolution and the rightful rulers of the world. They operate through rapid agricultural expansion and the elimination of ecological competition.

Indigenous, hunter-gatherer, and early pastoralist cultures that live in accordance with the laws of natural competition. They view humanity as a participant in the ecosystem rather than its master. Their lifestyle relies on adapting to natural limitations rather than attempting to exert total control over the environment.

A wealthy Jewish merchant who lost his family in the Holocaust. He purchases a gorilla from a traveling show and houses him in a modified gazebo on his estate. Recognizing the animal's immense intelligence, he provides an extensive education in human history and science, serving as a surrogate father figure and intellectual partner.

Walter Sokolow's daughter, who develops a close bond with her family's unique companion as she grows up. She becomes an intellectual prodigy through secret tutoring sessions. She eventually takes over the responsibility of ensuring there is a safe place for her mentor to live and conduct his philosophical teachings.

Walter Sokolow's wife and Rachel's mother. Unlike her husband and daughter, she is kept entirely unaware of the telepathic abilities and immense intelligence residing in the gazebo. She views the animal merely as a standard pet kept on the family estate and controls the financial resources associated with his upkeep.

An employee working at the grand Sokolow mansion. He is familiar with the telepathic abilities and history of the family's unique resident. He answers the door and provides basic information regarding the Sokolow household to visitors.

A man associated with the Daryl Hicks Carnival who purchases a new attraction for his show. He views his acquisition strictly as a financial asset, haggling over prices and prioritizing his business investments over animal welfare.