What I have found interesting in this thread is how quickly we now seem
to turn to the Web as a research tool. Indeed, this list-serve is an
often-useful resource!
My first reaction would have been to reach for my copies of "The Book of
the Cosmos - Imagining the Universe from Heraclitus to Hawking" (edited
by Dennis Danielson), or "Cosmology - Historical, Literary,
Philosophical, Religious, and Scientific Perspectives" (edited by
Norriss Heatherington).
In the latter, we find a discussion of the pre-Socratics of the 6th and
5th centuries BC. Notably, on page 55 we read that "One major tradition
within pre-Socratic science of the sixth and fifth centuries B.C. was
that established by Ionian peoples, who flourished among the Aegean
Islands and along the western coast of Asia Minor. A primary
characteristic of their philosophical inquiries into the nature of the
universe seems to have been a search for a basic substance or substances
that persist throughout all changes."
On following pages we find a discussion of Thales of Miletus (~ 580
BCE), who apparently thought of water as the basic substance.
Anaximenes (~560 BCE?), a student of Anaximander identified air as the
basic substance. Heraclitus (~500 BCE) argued that fire was basic.
Xenophanes (~570-475 BCE) proposed that there were two elements, water
and earth. Empedocles (~500-430 BCE) seems to be the first to use four
as the number of elements, and to identify them as earth, air, fire, and
water.
********************************************
"I am a theoretical physicist, and it is
common knowledge that theoretical
physicists often start out as amateur
theologians." - Bryce DeWitt
********************************************
Dr. George Spagna
Chair, Physics Department
Randolph-Macon College
P.O. Box 5005
Ashland, VA 23005-5505