Evolving Towards Air, Earth, Fire and Water: The Pre-Socratics
In the beginning there were only naked eye observations available from which to build a model
of the Solar System. As all motion is relative, it can be
difficult to discern what objects are at rest, and what objects
move relative to the objects which are at rest.
This difficulty partially can explain why the early geocentric model
(earth at center of solar system) was used as a device to explain planetary motions -
even though it was not necessarily the correct model.
Of course, this earth-centered model also plays into a cultural bias in that if you
think your special in the Universe, then you necessarily occupy a special place in
the Universe - that is, your located at the center of the Universe.
The early Greeks made much of this model so that's where we will begin our
exploration of the solar system starting with Pre-socratics (600-400BCE). The
Pre-socratics reasoned the cause of phenomena from a natural viewpoint rather than relying on of divine/supernatural intervention. This is a departure
from the older ideas of myth as an explanation for the birth of the Universe and
that change comes from interaction of Forces and Elements, not Gods.
In addition to this form of science,
these early Greeks also fundamentally examined the nature of the Universe (or Kosmos) and
assumed that it had to behave in an orderly, rational, and logical manner.
One of the chief features of the Pre-socratics is its reductionist nature. That is, given a complex system (like the Earth,
the weather, the Universe) the Greeks sought to reduce it down to a small number
of fundamental elements out of which everything can be built. Ideally, the number
of fundamental elements could be reduced to 1.
The first Pre-Socratics proposed that everything is made out of
four elements and it was the interaction among these four elements that
produced all the observed complexity in the world.
This idea would prevail for many centuries.
The First Table of Elements:
For example, Anaximenes of Miletos, (585-528 BCE) argued that air was the most fundamental element of the four. Earth was
some sort of condensation of air, while fire was some sort of emission from
air. When earth condenses out of air, fire is created in the process.
Heraclitus (535-475BCE) asserted that fire was the base element.
Empedocles (490-430 BCE) established the concept that each of the four
substances were eternal and indestructible and different combinations
of these elements produced everything in existence. What governed the
combinations was a balance of divine forces "Love and Strife". Love acted to combine the
four elements and Strife separated them out.
The concept of change troubled the pre Socratics because the purpose of
philosophy was to find the basis of all, that is, something eternal and fixed
amid all the observed
annhilation and creation. As stated above, rules needed to be established to reason
the cause of change and to find the eternal. Empedocles allowed for the
eternal to exist as the four elements and their combination to be the
changing quantity. Note that the concept of an "eternal" requirement is imposed
due to a human need rather than a purely observed phenomena, which of course
is impossible.
For the modern person this all sounds very unscientific but one must
consider that philosopy, science and religion were not
distinct from one another at this time. Notice that as Empedocles attempts to find a cause for change (science)
but he also asserts that the cause is due to divine forces (religion).
The Atomist Philosophy
However, all of the above were not universally accepted.
The most notable detractor was
Democritus who postulated the
existence of indestructible atoms ( from the Greek a-tome:
that which cannot be cut) of an infinite variety of
shapes, sizes and types.
He imagined an infinite universe containing an
infinite number of such atoms, in between
the atoms there is an absolute void. Worse still is the notion that the Universe itself
is a series of random interactions which can not be
predicted. This runs dead counter to the requirement stated earlier that the Universe
is orderly, rational, and logical
So now we have a genuine conflict: Either the Universe is random
(this is known as the atomist view)
, or the Universe is
deterministic and has predictable behavior once your know the rules. The data (e.g.
observations) support both views Cultural bias therefore influences
what view is adopted (for instance Plato, Aristotle's teacher, hated his ideas).
Often times then data is distorted to then support this culturally
preferred view or model.