S-Matrix Interpretation of Quantum Theory

The usual interpretation of quantum theory is clouded by the following points. (1) Invalid classical concepts are ascribed fundamental status. (2) The process of measurement is not describable within the framework of the theory. (3) The subject-object distinction is blurred. (4) The observed system is required to be isolated in order to be defined, yet interacting in order to be observed. These problems are resolved in a straightforward way by the unequivocal acceptance of a thoroughly pragmatic $S$-matrix viewpoint. This interpretation is described, and it is explained how and why the full physical content of quantum theory resides in the $S$ matrix.