  The purpose of this paper is to sketch an approach towards a reconciliation
of quantum theory with relativity theory. It will actually be argued that these
two theories ultimately rely on one another. A general operator-algebraic
framework for relativistic quantum theory is outlined. Some concepts of
space-time structure are translated into algebra. Following deep results of
Buchholz et al., the key role of massless modes, photons and gravitons, and of
Huygens' Principle in a relativistic quantum theory well suited to describe
"events" and "measurements" is highlighted. In summary, a relativistic version
of the "ETH Approach" to quantum mechanics is described.
