Learning is becoming an urgent topic. Nations worry about the learning of their citizens, companies about the learning of their workers, schools about the learning of their students. But it is not always easy to think about how to foster learning in innovative ways. This book presents a framework for doing that, with a social theory of learning that is ground-breaking yet accessible, with profound implications not only for research, but also for all those who have to foster learning as part of their responsibilites at work, at home, at school.