Correlations between mental and material states are an intrinsic feature of mind-matter models
which consider such states as dual aspects of an underlying reality that itself is neither mental
nor material. An early version of such a model is due to Spinoza, and since then variants thereof
have recurrently been formulated, mostly outside philosophical mainstream directions. Well-
known names in the modern philosophical history of dual-aspect monism are Strawson, Nagel,
and Chalmers. From the perspective of philosophically interested scientists, Wolfgang Pauli and
C.G. Jung are to be mentioned (in addition, e.g., Bohm and d’Espagnat).
In a series of publications, partly with a history-of-science flavor, we could systematically re
construct the most significant characteristics of the ideas of Pauli and Jung. For this purpose,
the comprehensive correspondence of Pauli, edited in eight volumes by Karl von Meyenn, was
enormously helpful. We worked out how the apparently related position of neutral monism
(Mach, James, Russell) deviates from the conception of Pauli and Jung. A key difference is that
the psychophysically neutral reality in the Pauli-Jung scheme is empirically accessible only in an
fashion, through its aspects.