Mathematics has a certain mystique, for it is pure and ex- act, yet demands remarkable creativity. This reputation is reinforced by its characteristic abstraction and its own in- dividual language, which often disguise its origins in and connections with the physical world. Publishing mathematics, therefore, requires special effort and talent. Heinz G|tze,who has dedicated his life to scientific pu- blishing, took up this challenge with his typical enthusi- asm. This Festschrift celebrates his invaluable contribu- tions to the mathematical community, many of whose leading members he counts among his personal friends. The articles, written by mathematicians from around the world and coming from diverse fields, portray the important role of mathematics in our culture. Here, the reflections of important mathematicians, often focused on the history of mathematics, are collected, in recognition of Heinz G|tze's life-longsupport of mathematics.

What is the logic of design process? Departing from this question, Tiago da Costa e Silva investigates the characteristic feature of every projective activity, for instance, in architecture, design, engineering design, and in the arts. In opposition to predominant views that understand design processes as mechanical and deterministic, this study, with the help of the semiotics of Charles S. Peirce, characterizes design activities as continuous and serendipitous interplays of esthetic and abductive processes that define rules and manifest forms. Tiago da Costa e Silva concludes that invention and discovery, manifested in the form of processes of abduction, actively pervade every development in any given context of design process.