Middle Ages: Ockham’s razor that guides brilliant minds – 11/19/2023 – Science

All things being equal, the simplest solution is usually also the most likely. With this and similar phrases, the principle proposed by a 14th century Franciscan monk became popular and was applied in various fields, from science to logic, and remains valid.

This monk, one of the greatest philosophers of medieval Europe, was called William. And because he was born in the small village of Ockham, in the south of England, he went down in history as William of Ockham.

His ideas about freedom and the nature of reality influenced political philosopher Thomas Hobbes and helped fuel the Protestant Reformation.

During his career he managed to offend the rector of Oxford University, disagree with his own ecclesiastical order and be excommunicated by the Pope. He declared that the authority of rulers derives from the people they govern and that Church and State should be separated.

He further insisted that science and religion should never mix, because science is based on reason, while religion derives from faith. Consequently, he provoked ire for using scientific logic to refute Aquinas’s five rational proofs for the existence of God.

Hence his then transgressive statement: “The existence of God cannot be deduced by reason alone.”

But no matter how turbulent his life was and no matter how interesting and valuable his work, his name continued to be mentioned more because of its association with that principle of simplicity. His idea was that philosophical arguments should be kept as uncomplicated as possible, something he himself practiced severely with his theories and those of his predecessors.

Centuries later, when it had already been applied by several brilliant minds, this idea would be called Ockham’s or Occam’s razor.

A mental shortcut

A philosophical razor is a mental shortcut that can help arrive at better explanations of a phenomenon, ruling out unnecessarily complex or unlikely hypotheses.

And there are many razors like Hitchens: “What is asserted without evidence can be rejected without evidence.” Or Hanlon’s: “Never attribute to malice that which can be adequately explained by stupidity.”

Ockham expressed his opinion in a somewhat opaque way, but there are versions by other authors that give a clearer idea.

There is one much earlier than Ockham, written by none other than Aristotle, in Second Analytics:

“We can assume the superiority, other things being equal, of the demonstration that derives from fewer postulates or hypotheses.”

Or perhaps “it is futile to do with more what can be done with less”, “an explanation of the facts should not be more complicated than necessary” or, faced with a crossroads, “the simplest solution is usually the best. successful.”

But if you’re curious to know what Ockham’s idea was, he conceived it when he was reflecting on what lay beyond the Earth. “It seems to me that the matter in the heavens is of the same kind as the matter here below. And this is because plurality must never be postulated unnecessarily.”

These heavens were also on the mind of an early adopter of his razor: Nicolas Copernicus.

In the Commentariolus of 1543, he declared that the “monstrous” complexity of the dominant idea that astronomical bodies revolved around the Earth “could be resolved with fewer constructions and in a much simpler way.”

The geocentric model of the universe that has prevailed since the time of the ancient Greeks has become increasingly complicated.

Observations of the planets’ motions required adjustments, such as adding epicycles after epicycles and moving Earth slightly away from the center of all other bodies’ orbits.

Seeking simplicity, Copernicus arrived at the model of planets orbiting the Sun, which was still somewhat complicated but nothing like the previous one.

Interestingly, Claudius Ptolemy, the 2nd-century Greek mathematician, astronomer, and geographer famous for his geocentric theory that Copernicus overturned, declared something akin to Ockham’s razor: “We consider it a good principle to explain phenomena by the simplest possible hypothesis.”

In any case, Copernicus was not the only renowned devotee of the razor.

In 1632, Galileo Galilei, making a detailed comparison of the Ptolemaic and Copernican models of the Solar System, argued that “nature does not multiply things unnecessarily; it uses the easiest and simplest means to produce its effects; it does nothing in vain.”

Isaac Newton, in turn, made Ockham’s principle one of his three “Rules of Reasoning in Philosophy” at the beginning of Book 3 of Principia Mathematica (1687). The first says that we should not admit more causes of natural things than those that are true and sufficient to explain their appearances.

“Nature,” he added, “takes pleasure in simplicity.”

A century later, in his Critique of Pure Reason, Immanuel Kant cited the maxim that “the rudiments or principles should not be multiplied unnecessarily” and maintained that it was a regulative idea of ​​pure reason that underpinned scientists’ theorizing about nature.

History is full of similar stories of scientists who let simplicity guide them to a better understanding of reality. But let’s close this account with Albert Einstein, who wrote:

“The great goal of all science is to cover the greatest possible number of empirical facts through logical deductions from the smallest possible number of hypotheses or axioms.”

Precaution

Ockham’s razor, then, impels us to choose the simplest explanations for any phenomenon we observe. If you see a light moving across the sky, before you suspect that it is a flying saucer, think that it is more likely to be an airplane or a satellite, or that you were lucky enough to see a shooting star.

Following this principle, medical students are advised, “When you hear the sound of hooves, think of horses, not zebras,” to guide them to look first for the simplest diagnosis that explains their patients’ symptoms.

This razor is, in many ways, the precursor of modern probability theory and has served in fields as diverse as physics, economics, philosophy and design. Scientists continue to invoke it on topics ranging from the origins of greed to cosmic dark matter.

But like any knife, it must be used with caution. Ockham’s principle is generally considered a heuristic principle, that is, a general rule that with experience has proven to be a useful tool, but without a solid logical or theoretical basis.

It’s not a law.

Blindly choosing explanations simply because they are simpler would imply, for example, getting rid of theories such as evolution, despite the scientific evidence that supports it.

By comparison, the unscientific theory of creationism, that all life came about as it does today thanks to a supernatural creator, is simpler.

But that doesn’t necessarily mean it’s correct.

To paraphrase something Einstein said in a lecture in 1933, everything should be as simple as possible, but not simpler.

Furthermore, eliminating any apparent complexity can frustrate lines of inquiry or restrict the imagination.

Outside the world of science, in areas such as politics or public opinion, where Ockham’s razor has found space, it can sometimes be limiting, some thinkers warn.

Social issues are often more complicated than the political speeches and strident opinions reflected in the media or social media.

Seemingly simple and unambiguous views are seductive because they seem to offer clarity.

However, to truly gain clarity on a topic, it is often vital to understand its complexity. And it may be surprising how much simpler they become upon closer examination.

Therefore, the trick is to learn to use Ockham’s razor in a thoughtful and strategic way to understand reality well.

This text was originally published here.