  The present state of QFT is analysed from a new viewpoint whose mathematical
basis is the modular theory of von Neumann algebras. Its physical consequences
suggest new ways of dealing with interactions, symmetries, Hawking-Unruh
thermal properties and possibly also extensions of the scheme of renormalized
perturbation theory. Interactions are incorporated by using the fact that the
S-matrix is a relative modular invariant of the interacting- relative to the
incoming- net of wedge algebras. This new point of view allows many interesting
comparisions with the standard quantization approach to QFT and is shown to be
firmly rooted in the history of QFT. Its radical ``change of paradigm'' aspect
becomes particularily visible in the quantum measurement problem. Key words:
Quantum Field Theory, S-matrix Theory, Tomita-Takesaki Modular Theory.
