In "Alias Grace," Margaret Atwood presents the idea that a prison acts as a barrier, confining its inmates while simultaneously isolating outsiders. This metaphor highlights how physical confinement can reflect deeper emotional or psychological barriers that individuals create around themselves. The notion emphasizes the complexity of personal and societal imprisonment, where the true shackles may lie within one's mind rather than just in physical spaces.

The quote concerning self-constructed prisons underlines the theme of entrapment that runs throughout the novel. It suggests that Grace, the main character, is not only confined by her circumstances but also by her own thoughts and experiences. Atwood's exploration of identity and memory reveals how individuals can become their own worst enemies, trapping themselves in patterns of thought that impede their freedom, both emotionally and psychologically.