Artificial systems now perform a striking range of cognitive tasks. This Element defends three claims. First, the status quo for cognitive work cannot survive. Whatever AI's trajectory, the package of features defining cognitive work – high skill requirements, credentials, wage premiums, resistance to automation, and low productivity growth – will be radically transformed. Second, the widespread displacement of humans from cognitive work, though it sounds alarming, may pose no special threat to human flourishing. Whatever makes work good for people is equally available outside cognitive work, and displacement enables leveraged gains in research and access to justice. Third, a world of ubiquitous cognitive assistance, though it sounds benign, carries distinctive moral risks, especially for children. Cognitive assistance works by reducing cognitive difficulty. But cognitive difficulty is necessary for the normal development of executive function – the capacities constitutive of autonomous agency. This title is also available as Open Access on Cambridge Core.