It’s easy to be pessimistic these days. We know that inequality has increased dramatically over the past two generations. Its ravages are increasingly impossible to ignore. But the grand sweep of history gives us reasons for hope. In this short and surprisingly optimistic history of human progress, the world’s leading economist of inequality shows that over the centuries we have been moving, fitfully and inconsistently but inexorably, toward greater equality. Thomas Piketty guides us through the seismic movements that have made the modern world: the birth of capitalism, the age of revolution, imperialism, slavery, two world wars, and the building of the welfare state. He shows that through it all, societies have moved toward a more just distribution of income and assets, reducing racial and gender inequalities and offering greater access to health care, education, and the rights of citizenship. To keep moving, he argues, we need to commit to legal, social, fiscal, and educational systems that can make equality a lasting reality, while resisting the temptations of cultural separatism. At stake is the quality of life for billions of people. We know we can do better. But do we dare?