A concept invented by Robert Heinlein in his novel
Stranger in a Strange Land. A Fair Witness is a
professional observer; a person with eidetic memory and keen
observational skills, admitted to testify in court about any
factual aspect of a situation e was retained to
record. A Witness could be thought of as performing a function similar
to that of a notary public, but much more so. Unlike notarys, the
members of the Fair Witness Guild are highly respected professionals,
and obviously guild members are held to extremely high standards of
integrity and ethics.
In addition to perfect recall, the hallmark of a Fair Witness is that e will never render any
opinion about what e observed, nor infer anything that e
did not actually see or hear.
The book was first published in 1961, and some people might suppose
that the concept of the Fair Witness has been rendered obsolete by
the march of progress; that the ubiquity of audio, visual, and other
types of recording devices would make them preferable. (For example,
in The Truth Machine by James Halperin, there comes a time when
virtually everybody wears a life recorder that records, and stores
in a huge central repository, emselves and eir surroundings virtually
every minute of the day.)
However, it seems possible to me that, with the advances in the techniques
and availability of manipulation of digital data, we may yet find that
we are more willing to put our trust in such people than in images and
sounds the veracity of which we no longer can take for granted.