Today’s Enlightenment stems from new understandings and practices that have taken hold in the social sector and are producing better and measurable results against a range of problems. In Fixes, for example, we have asked questions like: Is it possible to systematically increase empathy and cooperation in children? Is there a way to teach math so virtually all children become proficient? Can we prevent thousands of cases of child abuse without removing children from their parents? Can we dramatically reduce — or come close to eliminating — chronic homelessness from every city in the United States? What’s surprising is that the answer to these and many similar questions is yes. This is not wishful thinking. We know how to do these things; in fact, we’re currently doing them at significant scale (although nowhere near the scale of the problems). We’re accustomed to hearing that our problems are intractable, that social programs inevitably disappoint. So what’s different today?