I hesitate to define it, and therefore limit it, for the thousands now exploring its possibilities. Let’s tentatively call it a speculative movement: a collaborative effort to imagine and design a world of prosperity, peace, sustainability and beauty, achievable with what we have from where we are. Only in the twenty-teens could a series of social media sketches spark such an ambitious activist agenda — not to mention a literary genre that has rabid fans but has yet to produce any literature.