Co-Existence

The follow-up to the bestselling Co-Intelligence (100k shipped), Wharton Professor and creator of the ONE USEFUL THING substack (over 400k subscribers): a cutting-edge playbook for working, learning and living with the latest generation of AI. The follow-up to the bestselling Co-Intelligence: a guide to thriving at the jagged frontier where human and AI capabilities collide. AI isn't coming-it's already here. A billion people now use it every week. AIs can reason, plan, persuade, create, and collaborate in ways that once seemed impossible. Non-human intelligence is now embedded in nearly everything humans do. But AI capability isn't uniform. It's jagged-a landscape of sharp peaks where AI excels beyond human ability and deep valleys where it fails at tasks a child could master. This unevenness creates profound confusion: the same system that writes elegant code might fabricate a simple fact, or produce brilliant analysis while missing obvious context. In his bestselling Co-Intelligence, Ethan Mollick-a Wharton professor and author of the widely read One Useful Thing newsletter-showed readers how to use AI productively. In this urgent sequel, he argues that the jagged frontier, for all its instability, is where the future will be decided. If AI were uniformly better or worse than humans, the outcome would be clear: total replacement or marginal utility. Instead, uneven capability creates volatile overlaps between human and machine strengths. Most work now spans peaks and valleys-and humans are still best equipped to navigate that terrain. Clear, practical, and written with Mollick's signature wit, Co-Existence is the essential guide for anyone who needs to understand not just how to work with AI-but how to thrive at the frontier where human and machine intelligence meet.