  The human mind is constituted by inner, subjective, private, first-person
conscious experiences that cannot be measured with physical devices or observed
from an external, objective, public, third-person perspective. The qualitative,
phenomenal nature of conscious experiences also cannot be communicated to
others in the form of a message composed of classical bits of information.
Because in a classical world everything physical is observable and
communicable, it is a daunting task to explain how an empirically unobservable,
incommunicable consciousness could have any physical substrates such as neurons
composed of biochemical molecules, water, and electrolytes. The challenges
encountered by classical physics are exemplified by a number of thought
experiments including the inverted qualia argument, the private language
argument, the beetle in the box argument and the knowledge argument. These
thought experiments, however, do not imply that our consciousness is
nonphysical and our introspective conscious testimonies are untrustworthy. The
principles of classical physics have been superseded by modern quantum physics,
which contains two fundamentally different kinds of physical objects:
unobservable quantum state vectors, which define what physically exists, and
quantum operators (observables), which define what can physically be observed.
Identifying consciousness with the unobservable quantum information contained
by quantum physical brain states allows for application of quantum information
theorems to resolve possible paradoxes created by the inner privacy of
conscious experiences, and explains how the observable brain is constructed by
accessible bits of classical information that are bound by Holevo's theorem and
extracted from the physically existing quantum brain upon measurement with
physical devices.
