The purpose of this chapter is to examine the question of who is meant in this book when defining its mission to pursue ‘living well in a world worth living in for all.’ Who, or which, are ‘all’ in this phrase? The authors provocatively claim that the taken-for-granted starting point for most of the authors of this book seems to be the good life of humans, excluding the well-being of the rest of the community of life. The authors take deep-ecological and more-than-human thinking as their starting point, according to which the well-being of human species is dependent on the well-being of the global web of life. Anthropocentrism is the root cause of the ecological crisis that has befallen humanity and the entire planet. Rooted in the Aristotelian and Marxian tradition of praxis, the authors propose a posthuman interpretation of ‘living well,’ based on a review of deep ecology and posthumanism. This new interpretation of the praxis tradition is called praxis as planetary wisdom, defined as human action, aimed at human well-being which is intertwined with planetary well-being, including the well-being of present humans, future humans, and non-human nature. The way to achieve this wisdom is through ‘education for planetary well-being.’