Here is corroboration of Forrester's 5th principle from
David J. Chalmers, a leader thinker in the emerging field
of consciousness studies:
'There is an obvious problem that plagues the development of a
theory of consciousness, and that is the paucity of objective data.
Conscious experience is not directly observable in an experiemental
context, so we cannot generate data about the relationship between
physical processes and experience at will. Nevertheless, we all have
access to a rich source of data in our own case. Many important
regularities between experience and processing can be inferred from
considerations about one's own experience. There are also good
indirect sources of data from observable cases, as when one relies
on the verbal report of a subject as an indication of experience.
These methods have their limitations, but we have more than enough
data to get a theory off the ground.'
From Chalmers' often quoted paper. For the full paper, please
access his 1994 Tucson I paper.