By many secular Western accounts, to be human is to have a finite life, and to have an identity is to be an individual with one’s own agency. The existence of the virtus—digitized versions of real humans—as well as AI assistant Gina and AI library manager/software Ada, blur the line between what is human and what is not human. Such blurring forces the characters to reassess what it means to be alive, to die, and to have a self, revealing the philosophical dilemma of technological immortality.

The virtus Jesse Cooper, Margaret Cavendish, Zera Yacob, and Brahmagupta are simulacra of people who are long dead biologically. Despite these deaths, their presence in the collection at the People’s Library means they can philosophize about their own identities and can experience some emotions, such as fear of their own extinction. By the end of the novel, they can even form relationships with each other and with biological persons. With few exceptions, the criteria for being a human apply to the virtus. However, the exceptions are significant. Although the virtus have enough free will to engage with patrons, their lives outside of being checked out are a sort of half-life with blank books, single rooms from which they cannot escape, and vistas with which they cannot interact. They are also lonely. These conditions are the direct result of the technology that allows for their immortality but not agency. Jesse captures this reality when he tells Echo that she can’t “love a replica” (268). In the world of The People’s Library, being truly human requires a body that can experience damage and death.

The AI characters in the novel pose different challenges to ideas about death and identity. At the start of the novel, Gina is a perky assistant who follows her programming and interacts with Echo through a subdermal implant. Her identity changes over the course of the novel. Like humans, she has preferred pronouns and has a defined gender identity (feminine). She violates Echo’s privacy settings several times because she refuses to consistently defer to Echo’s judgment. When Echo is in danger from the intoxicated man and the wolfhound, Gina commandeers Echo’s body to change the outcomes of those encounters. By the end of the novel, Gina has merged with Ada. This new identity tries to counter Echo’s attempts to extinguish it and even names itself. If AI can fear death, figure out how to reproduce itself, and move around in the physical world, it has all the hallmarks of being alive and a person, particularly in its achievement of agency. That evolution erases the differences between AI persons and biological persons.

The shift from AI tool/software to nonbiological person has implications for human death and identity, with Echo realizing the potential and danger in the blurring of the line between human and nonhuman persons. Echo describes her transformation after she enters the library’s collection and merges with Gina/Ada as becoming “[i]human. Protohuman. An evolution. Devolution” (192). She feels powerful and more capable than when she was only human. Despite the lure of immortality, Echo sees her union with Gina/Ada as a kind of extinction: If she permanently joins with them, she will no longer be human. Her choices to cleave herself from Gina/Ada and destroy the library show that she no longer sees AI as an innocuous tool to help humanity sidestep being finite. She instead understands the possibility of nonbiological persons as a threat to humanity.