This volume is a collection of articles on themes related to the book *Laws of Form* by George Spencer-Brown. *Laws of Form* was first published in 1969 and brings forth a new articulation of the foundations of thought. In *Laws of Form* we have a mathematical formalism based on one symbol and an approach to the question how the world would appear if a distinction could be drawn. *Laws of Form* does not answer the question how, given nothing as a beginning, a distinction can, indeed must, inevitably take place. This second question must, in its own structure, be left to each individual thinker. Nevertheless, *Laws of Form*, beautifully written and content free (form is emptiness, emptiness is form) is the most powerful mathematical text on the edge of nothing that has been produced since Euclid's *Elements*. These papers are a tribute to Spencer-Brown and his singular achievement.