  We present a new derivation of the proof for the TCP/CPT Theorem using the
Dynamical Principle and Variation of Action methods first defined by Schwinger
in 1951. This new proof will significantly extend the TCP Theorem beyond the
original proofs by Pauli-Luders and Jost, which were significantly constrained
by limits of free quantum fields and the asymptotic condition. This paper gives
a more fundamental proof based on invariance of the Variation of Action with
interactions included and no free field or asymptotic condition on the quantum
fields. This new proof for TCP/CPT can now be applied to more complicated
quantum field systems that include n-particle bound states and unstable states.
