  Recent insights into the conceptual structure of localization in QFT
("modular localization") led to clarifications of old unsolved problems. The
oldest one is the Einstein-Jordan conundrum which led Jordan in 1925 to the
discovery of quantum field theory. This comparison of fluctuations in
subsystems of heat bath systems (Einstein) with those resulting from the
restriction of the QFT vacuum state to an open subvolume (Jordan) leads to a
perfect analogy; the globally pure vacuum state becomes upon local restriction
a strongly impure KMS state. This phenomenon of localization-caused thermal
behavior as well as the vacuum-polarization clouds at the causal boundary of
the localization region places localization in QFT into a sharp contrast with
quantum mechanics and justifies the attribute "holstic". In fact it positions
the E-J Gedankenexperiment into the same conceptual category as the
cosmological constant problem and the Unruh Gedankenexperiment. The holistic
structure of QFT resulting from "modular localization" also leads to a revision
of the conceptual origin of the crucial crossing property which entered
particle theory at the time of the bootstrap S-matrix approach but suffered
from incorrect use in the S-matrix settings of the dual model and string
theory. The new holistic point of view, which strengthens the autonomous aspect
of QFT, also comes with new messages for gauge theory by exposing the clash
between Hilbert space structure and localization and presenting alternative
solutions based on the use of stringlocal fields in Hilbert space. Among other
things this leads to a radical reformulation of the Englert-Higgs symmetry
breaking mechanism.
