  This paper is a top down historical perspective on the several phases in the
development of probability from its prehistoric origins to its modern day
evolution, as one of the key methodologies in artificial intelligence, data
science, and machine learning. It is written in honor of Barry Arnold's
birthday for his many contributions to statistical theory and methodology.
Despite the fact that much of Barry's work is technical, a descriptive document
to mark his achievements should not be viewed as being out of line. Barry's
dissertation adviser at Stanford (he received a Ph.D. in Statistics there) was
a philosopher of Science who dug deep in the foundations and roots of
probability, and it is this breadth of perspective is what Barry has inherent.
The paper is based on lecture materials compiled by the first author from
various published sources, and over a long period of time. The material below
gives a limited list of references, because the cast of characters is many, and
their contributions are a part of the historical heritage of those of us who
are interested in probability, statistics, and the many topics they have
spawned.
