Beyond the hype and above the panic: how autonomous AI reshapes work, competition, and power, and the judgments that decide where it leads.

The agentic AI conversation has hardened into two camps—the champions who promise frictionless transformation and the cynics who forecast societal collapse. But neither can help the person who actually has to make tangible decisions on any given day: the business leader who must choose where to deploy an autonomous agent; the investor who wants to separate signal from circular financing; the policymaker who writes rules that will shape a decade; or the rest of us living through a world in flux.

When Machines Act is the compass for the disciplined middle. In this book, Jeffrey Sonnenfeld, David Siegel, and Stephen Henriques offer readers a clear account of the defining shift of the decade: the arrival of autonomous AI. These are systems that no longer merely answer questions but take actions, make decisions, and execute work across an entire organization or an individual’s daily life.

The book draws on decades of collective experience across the authors—as either world-renowned advisors to Fortune 500 CEOs, pioneering technologists of the computing age, or investors in major public and private enterprises. Informed by dozens of expert interviews with leaders in technology and off-the-record dialogues with more than 300 chief executives at the Yale CEO forums, it distills essential principles you can carry into a boardroom, a statehouse, or a kitchen-table conversation.

Written from inside the rooms where the choices are being made, When Machines Act is an engaging, clear-eyed, and enduring guide to our collective future.