The New Natural Law (NNL) theory grounds practical deliberation in principles directing rational agents toward the pursuit of goods that are intrinsic dimensions of human flourishing, individually and in community. Work has consistently been identified as one such good, as an integral and constitutive aspect of human well-being worth engaging in for its own sake. Initially, NNL theorists distinguished the goods of work and play, but they have more recently sought to identify the core of the good of work in such a way as also to encompass the good of play, as “excellence in activity engaged in for its own sake.” This chapter investigates a number of questions addressed or raised by the NNL approach: what differentiates work from play? Whence come the standards of excellence that are essential to the goods of work and play? And what ethical norms should govern human engagement in work and play? Finally, the chapter will take up the question of work from a theistic standpoint: in what way are human and divine work related, both in this life and in relation to the Kingdom of Heaven?