Occam's Razor

Applying the "Law of Parsimony" (aka - Occam's Razor) to Christianity highlights its fundamental lack of credibility. For each of the thorny challenges to Christianity (the problem of evil, the failure to answer prayers, god's invisibility and elusiveness, the lack of solid and uncontroversial evidence, god's ability to defy laws of physics, the existence of an afterlife, angels and demons) Christian apologists have handy, glib, overly ornate, ad hoc explanations:

• God doesn't let us see him because he is testing our faith
• If god gave us incontrovertable evidence it would interfere with our free will
• He allows evil in the world for a whole variety of stunningly incompatible and far-fetched reasons
• The fossil record gives the appearance of an ancient past to test our faith, or even that fossils were planted by the devil
• Atheists don't accept miracles because they have closed their mind and heart to god.
• God sometimes does and sometimes does not answer prayers, depending on his mysterious mood, etc.
• The bible is inerrant - you're just mis-reading it!
• Why would someone (i.e., Christian martyrs) die for a lie?

Each of the above explanations favors an active god to account for experiences that could better be explained by the complete absence of a god. The god explanation is strained and reeks of artifice. That is, it feels ad hoc, designed merely to cover the facts but provides no additional predictive or descriptive power over and above the secular explanation. It is designed to provide a cover story for what has already happened in our universe (e.g., the six days of creation, the flood, etc), but is utterly incapable of making novel predictions about future events, or even mundane predictions. It is completely untestable, and designed to be immune from refutation. Philosophers would say that the secular theory and the religious theory are "underdetermined" by the facts (i.e., the observations underdetermine several competing theories), in that each accounts for the facts so far. Occam's Razor is a tool that can be used to help decide between competing, seemingly equivalent theories.

It was named after William of Ockham, who is thought to have originated the most well-known version of it 700 years ago. The word, "razor" is part of the name because this principle is used to "shave away" needless embellishments and unnecessary assumptions from from hypotheses and explanations. A formal phrasing of it is,

Entities should not be multiplied beyond necessity

which means we would be wise to seek out the most economical explanation that will fully account for the facts. We see this restated and reinvented from time to time, as with the "KISS" principle ("Keep it simple, stupid"), and a phrase commonly used in medicine where there can be a tendency to over-diagnose, “When you hear hoofbeats, think horses, not zebras”. It is also called the "Law of Economy" or the "Law of Parsimony". They all mean basically the same thing - choose the explanation which requires the smallest number of "inventions". For the teacher hearing a student's story about why they didn't turn in an assignment, the explanation which involves the student being lazy requires a smaller leap of faith than that the dog ate the homework.

This guideline does not PREVENT us from denying the existence of these extra entities (i.e., the destructive dog, the rampaging zebra). Dogs are occasionally the guilty party, and probably there has been the rare case of the zebra on-the-loose. But experience shows that it is usually the simpler explanation - the student procrastinated, the hoofbeats were those of a horse. However, it allows us to refrain from including superfluous ornamentation of the explanation in the absence of a compelling reason. In part, this is because human beings can never be sure they know what is and what is not “beyond necessity”; the necessities are not always clear to us.

The application of the principle can help shifts the burden of proof in a discussion to the party making the exaggerated claims. The Razor is a "best practice" for approaching problems. It states that one should utilize simpler theories that can fit the evidence and explain the process or phenomenon under investigation. The simplest available theory need not be most accurate. The exact meaning of "simplest" may be debatable, and people will argue of what "fitting the evidence" really means. Also, since the only reason to abandon the guideline is be confronted with a "compelling reason", the apologist will therefore construct such reasons, typically using one of the standard arguments such as the Cosmological Principle, the Fine Tuned Universe, the Ontological Argument, or the Design Implies a Designer argument. These, and others, are discussed in other sections of this blog.

Applied to Christian apologetics, we are presented with two explanations. One posits god's involvement vs. one that does not. The second is less complex and should be preferred in the absence of a reason not to. It does not require the invention of a super-being who is certainly is far more complex than the universe he created and continues to control (although I have heard Christians perversely argue that, on the contrary, god is the simplest of beings!). So, barring any compelling evidence to the contrary, the non-supernatural reason should be preferred. By the standard of Occam's Razor, the explanation that does NOT involve a god, afterlife, heaven, hell, virgin births, parting seas, pillars of salt, burning bushes, talking snakes and donkeys, exorcisms, stopping the sun, walking on water, resurrections, salvation and assorted miracles is, by far, a superior explanation for what we see here in our lives. As additional confirmation, it doesn't hurt that the naturalistic explanation has a perfect 500 year long batting average (I am starting with the Renaissance, here, though it could be argued that it began with the Greek philosophers). Never has a natural explanation fallen to a supernatural one, though the opposite frequently occurs.

If we have no good evidence for likely candidates for a supernatural event, then we clearly have no reason to postulate supernatural causation. Refusing to accept the existence of supernatural causes, however, is not equivalent to rejecting their existence. Accepting the natural explanation requires us to deny the existence of supernatural causes altogether. Occam's Razor provides us with grounds for denying the existence of supernatural causation rather than remaining agnostic about it. If we have no convincing evidence in support of the supernatural explanation for our experiences, the simplest explanation is that there are no supernatural causes influencing the natural world. Second-hand testimony, apocryphal stories, ancient documents, testimony based on personal experience, revelation, and other weak evidence for possible supernatural events can always be explained more simply than the actual occurrence of such events. It is far more likely that the testimony or evidence can be more cleanly explained in terms deception, fraud, exaggeration, imagination, poetic license, hallucination, memory errors, misunderstanding, wishful thinking, propagandizing, perceptual errors, mistranslation, or misinterpretation.

Issac Newton, although a very devout Christian, had no tolerance for what he called “occult causes” both because he saw them not only as unnecessary, but positively unhelpful. They had no explanatory power, but were simply excuses for explaining away what we didn’t yet understand. In his day, the nature of magnetism, electricity, gravity, optics, cohesion, friction, thermodynamics, fermentation, cell biology, and other natural phenomena were not well understood. Pretty much 80% of what is in a Freshman College physics textbook had not been discovered yet (he did have Galileo to rely on, but not a lot more). He envisioned that from the confusion that then reigned, laws of nature would emerge to resolve those mysteries. He criticized the Aristotelians (as we criticize Christians) for ascribing occult causes to incomprehensible natural phenomena by correctly observing that “such occult qualities put a stop to the improvement of natural philosophy, and therefore of late years have been rejected. To tell us that every species of things is endowed with an occult specific quality by which it acts and produces manifest effects is to tell us nothing”. Even so, he himself subscribed to two seemingly occult entities – the invisible force called “gravity”, and the luminiferous ether through which he believed light traveled.

However, it is important to keep in mind that he lived on the historical edge of the scientific revolution. During his lifetime, there was not a clear distinction between chemistry and alchemy, between the natural and the supernatural, between science and magic. He helped to refine those distinctions in many ways, not the least of which was an often reprinted work of just a few pages called “Rules of Reasoning in Philosophy”. It was a simple guide to help thoughtful observers make sense of their experiences in the natural world.

He enumerated four rules for understanding real world “natural philosophy” (i.e., science) problems. I won't present all of them, but one in particular applies in this context:

We are to admit no more causes of natural things such as are both true and sufficient to explain their appearances. To this purpose the philosophers say, that Nature does nothing in vain, and more is in vain, when less will serve; for Nature is pleased with simplicity, and affects not the pomp of superfluous causes.”

Newton was not alone in originating his own version of the Razor. Other philosophers such as Aristotle, Scotus, Maimonides, and Ptolemy restated this principle. According to Ptolemy, "We consider it a good principle to explain the phenomena by the simplest hypothesis possible." Phrases such as "It is vain to do with more what can be done with fewer" and "A plurality is not to be posited without necessity" were commonplace in the middle ages.

Even religious scholars such as Thomas Aquinas followed this rule. He said, "it is superfluous to suppose that what can be accounted for by a few principles has been produced by many".