AI now helps people with wedding toasts, tax returns, and processing the trauma of war. The technology’s generality lets it occupy roles that used to be human-only: assistant, tutor, friend, lover, therapist. It is endlessly patient, always available, and—unlike any prior tool—an active participant in our cognitive lives. While past tools let us externalize discrete mental processes—notebooks for memory, calculators for computation, maps for navigation—AI widens the aperture. Now, summarizing