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Occam's Razor - what is it?

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DawnoftheForest

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Apr 18, 2002, 9:18:08 AM4/18/02

Occam's Razor
"Pluralitas non est ponenda sine neccesitate" or "plurality should not be
posited without necessity." The words are those of the medieval English
philosopher and Franciscan monk William of Ockham (ca. 1285-1349). Like many
Franciscans, William was a minimalist in this life, idealizing a life of
poverty, and like St. Francis himself, battling with the Pope over the issue.
William was excommunicated by Pope John XXII. He responded by writing a
treatise demonstrating that Pope John was a heretic.

What is known as Occam's razor was a common principle in medieval philosophy
and was not originated by William, but because of his frequent usage of the
principle, his name has become indelibly attached to it. It is unlikely that
William would appreciate what some of us have done in his name. For example,
atheists often apply Occam's razor in arguing against the existence of God on
the grounds that God is an unnecessary hypothesis. We can explain everything
without assuming the extra metaphysical baggage of a Divine Being.

William's use of the principle of unnecessary plurality occurs in debates over
the medieval equivalent of psi. For example, in Book II of his Commentary on
the Sentences of Peter Abelard, he is deep in thought about the question of
"Whether a Higher Angel Knows Through Fewer Species than a Lower." Using the
principle that "plurality should not be posited without necessity" he argues
that the answer to the question is in the affirmative. He also cites
Aristotle's notion that "the more perfect a nature is the fewer means it
requires for its operation." This principle has been used by atheists to reject
the God-the-Creator hypothesis in favor of natural evolution: if a Perfect God
had created the Universe, both the Universe and its components would be much
simpler. William would not have approved.

He did argue, however, that natural theology is impossible. Natural theology
uses reason alone to understand God, as contrasted with revealed theology which
is founded upon scriptural revelations. According to Occam, the idea of God is
not established by evident experience or evident reasoning. All we know about
God we know from revelation. The foundation of all theology, therefore, is
faith. It should be noted that while others might apply the razor to eliminate
the entire spiritual world, Ockham did not apply the principle of parsimony to
the articles of faith. Had he done so, he might have become a Socinian like
John Toland (Christianity not Mysterious, 1696) and pared down the Trinity to a
Unity and the dual nature of Christ to a single nature.

William was somewhat of a minimalist in philosophy, advocating nominalism
against the more popular view of realism. That is, he argued that universals
have no existence outside of the mind; universals are just names we use to
refer to groups of individuals and the properties of individuals. Realists
claim that not only are there individual objects and our concepts of those
objects, there are also universals. Ockham thought that this was one too many
pluralities. We don't need universals to explain anything. To nominalists and
realists there exist Socrates the individual and our concept of Socrates. To
the realist there also exist such realities as the humanity of Socrates, the
animality of Socrates, etc. That is, every quality which may be attributed to
Socrates has a corresponding "reality", a "universal" or eidos, as Plato called
them. William might be said to have been skeptical of this realm of plurality
called the realm of universals. It is not needed for logic, epistemology or
metaphysics, so why assume this unnecessary plurality? Plato and the realists
could be right. Perhaps there is a realm of eidos, of universal realities which
are eternal, immutable models for individual objects. But we don't need to
posit such a realm in order to explain individuals, our concepts or our
knowledge. Plato's Eidos (Forms) are excess and unnecessary metaphysical and
epistemological baggage.

It might well be argued that Bishop George Berkeley applied Occam's razor to
eliminate material substance as an unnecessary plurality. According to
Berkeley, we need only minds and their ideas to explain everything. Berkeley
was a bit selective in his use of the razor, however. He needed to posit God as
the Mind who could hear the tree fall in the forest when nobody is present.
Subjective Idealists might use the razor to get rid of God. All can be
explained with just minds and their ideas. Of course this leads to solipsism,
the view that I and my ideas alone exist, or at least they are all I know
exist. Materialists, on the other hand, might be said to use the razor to
eliminate minds altogether. We don't need to posit a plurality of minds as well
as a plurality of brains.

Occam's razor is also called the principle of parsimony. These days it is
usually interpreted to mean something like "the simpler the explanation, the
better" or "don't multiply hypotheses unnecessarily." In any case, Occam's
razor is a principle which is frequently used outside of ontology, e.g., by
philosophers of science in an effort to establish criteria for choosing from
among theories with equal explanatory power. When giving explanatory reasons
for something, don't posit more than is necessary. Von Däniken could be right:
maybe extraterrestrials did teach ancient people art and engineering, but we
don't need to posit alien visitations in order to explain the feats of ancient
people. Why posit pluralities unnecessarily? Or, as most would put it today,
don't make any more assumptions than you have to. We can posit the ether to
explain action at a distance, but we don't need ether to explain it, so why
assume an ethereal ether?

Oliver W. Holmes and Jerome Frank might be said to have applied Occam's razor
in arguing that there is no such thing as "the Law." There are only judicial
decisions; individual judgments and the sum of them make up the law. To confuse
matters, these eminent jurists called their view legal realism, instead of
legal nominalism. So much for simplifying matters.

Because Occam's razor is sometimes called the principle of simplicity some
simpleminded creationists have argued that Occam's razor can be used to support
creationism over evolution. After all, having God create everything is much
simpler than evolution, which is a very complex mechanism. But Occam's razor
does not say that the more simpleminded a hypothesis, the better. If it did,
Occam's would be dull razor for a dim populace indeed.

Some have even found a use for Occam's razor to justify budget cuts, arguing
that "what can be done with less is done in vain with more." This approach
seems to apply Occam's razor to the principle itself, eliminating the word
"assumptions." It also confuses matters by confusing "less" with "fewer." Occam
was concerned with fewer assumptions, not less money.

The original principle seems to have been invoked within the context of a
belief in the notion that perfection is simplicity itself. This seems to be a
metaphysical bias which we share with the medievals and the ancient Greeks.
For, like them, most of our disputes are not about this principle but about
what counts as necessary. To the materialist, dualists multiply pluralities
unnecessarily. To the dualist, positing a mind as well as a body, is necessary.
To atheists, positing God and a supernatural realm is to posit pluralities
unnecessarily. To the theist, positing God is necessary. And so on. To von
Daniken, perhaps, the facts make it necessary to posit extraterrestrials. To
others, these aliens are unnecessary pluralities. In the end, maybe Occam's
razor says little more than that for atheists God is unnecessary but for
theists that is not true. If so, the principle is not very useful. On the other
hand, if Occam's razor means that when confronted with two explanations, an
implausible one and a probable one, a rational person should select the
probable one, then the principle seems unnecessary because so obvious. But if
the principle is truly a minimalist principle, then it seems to imply the more
reductionism the better. If so, then the principle of parsimony might better
have been called Occam's Chainsaw, for its main use seems to be for
clear-cutting ontology.

See related entries on ad hoc hypotheses, control study, cold reading, communal
reinforcement, confirmation bias, the placebo effect, the post hoc fallacy,
selective thinking, self-deception, subjective validation, testimonials, James
Van Praagh, and wishful thinking.

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