Ockham's razor: what it is and how it is used in scientific research

Ockham's razor or principle of parsimony is a principle that prioritizes the simplest explanations of all possible to explain an event.

It seems simple, but this concept, coined as early as the 16th century, has accompanied human reasoning for hundreds of years in fields as disparate as medicine or statistics, through psychology, biology and music, among others disciplines.

Athough it does not seems, people inherently apply the principle of parsimony at almost all times without realizing it. For example, when a person is not at home when we wake up, we think that he will have gone out to buy something, instead of rambling about whether he has traveled to another country in search of a new life.

As much as it requires an exercise in abstraction and observing the term "outside itself", we can see that the razor Ockham's, or rather, simplification of thought, is a defining characteristic of the human being in many moments. If you want to know more about this fascinating topic, keep reading.

• Related article: "Null hypothesis: what is it and what is it used for in science"

Ockham's razor: simplifying reality

William of Ockham was a pioneering scholastic philosopher who lived from 1286 to 1347. To save us a history lesson, we will limit ourselves to saying that at this time the thoughts of Ancient Greece had been recovered through Al Andalus (Spain), which influenced various thinkers and philosophers in their postulation of methods and theories.

In addition to the golden rule of Ockham's razor or principle of parsimony, which is that the simplest explanation is usually the most likely, William of Ockham also he was governed by four iron dogmas in his works:

• It is futile to do something with more when it can be done with less.
• When a proposition holds true for two facts, assuming a third is superfluous.
• Plurality should not be assumed unnecessarily.
• Plurality cannot be assumed unless proven by reason, experience, or infallible authority.

Although we have presented these principles to you as a rudimentary translation from Latin, the general idea is clear. According to the principle of parsimony, in most cases less is more. It is necessary to emphasize that, even so, this application does not defend tooth and nail that the simplest hypothesis has to be true in all cases. Rather, it argues that this is the most likely and that among a set of theories to explain a fact, the best starting point is the simplest of all.

Examples of its application in science

Although this methodological principle can be very useful to lay the foundations on which to build knowledge, it is clear that it is not infallible. Various sources refute this, because as obvious as it may seem, sometimes reality cannot simply be reduced to the simplest processes. Below you can see examples of the use of Ockham's razor in various fields.

1. Parsimony and evolution

In the world of phylogenetics (the branch of science that is responsible for exploring the relationships between species and taxa of living things) the principle of parsimony is widely used.

When making phylogenetic trees, that is, detecting the ancestors and the branching of the species from them, in most cases the best hypothesis is the one that requires less evolutionary changes. Let's take an example:

If we look at insects and the presence or absence of wings in different taxa, we can ramble on various evolutionary mechanisms that explain this difference. Two of them could be the following:

The first is that common ancestor for all of them had wings. The fossils show that insects lost them at a certain evolutionary point, therefore, at some point certain taxa regained them. This would involve three steps (wings-not wings-wings again).

The second is that the common ancestor for all of them did not have wings. Fossils show that no insects were winged at one time, but throughout evolutionary history, some developed them from primary structures. This would involve two steps (wings- no wings).

According to the principle of parsimony or Ockham's razor, the second option is the most likely, as it requires fewer steps to explain the current evolutionary situation. Of course, these postulations are merely speculative to explain the principle here exposed and at no time do they conform to reality. We are simply trying to simplify the complexity of this method.

• You may be interested in: "What is the scientific method and how does it work?"

2. The razor and creationism

Just as this principle has been used extensively to generate evolutionary trees, creationist branches of thought have historically appropriated it to refute natural selection postulated by Darwin.

After all, according to various theologians, supposing the existence of an omnipotent creative force of a whole is a further explanation. simpler than trying to understand a biological selection force that modulates the adaptation of all living things throughout the ages. centuries.

In counterpoint to this thought, the zoologist Richard Dawkins postulates that if the universe has been created by a God, this must be explained as well. An entity capable of creating the universe must be infinitely more complex than the universe itself.Therefore, explaining this is a much more difficult task than understanding the origin of life without your intervention. This, as you may have guessed, would violate the principle of parsimony.

3. Parsimony and chemistry

In chemistry, the principle of parsimony can be applied by taking into account that the minimal "metabolic path" Among the precursor compounds and the products of a reaction, it is the most probable for obtaining said products.

This principle can be interpreted in such bizarre places as the chemical compound industry. For example, a manufacturer of paints is more interested in following the minimum number of steps necessary to obtain a specific color, as this reduces costs, time and labor.

Even so, It is necessary to recognize that Ockham's razor does not apply to many physiological chemical pathways at all., since the obtaining of many compounds in the human body and the environment can manifest itself in different routes. For example, the synthesis of some boron compounds show at least three different chemical pathways for the same purpose. This reality goes against the principle of parsimony, since in this case a more complex explanation dominates the set of reactions.

4. The razor in psychology and medicine

Again, this reductionist principle can be applied, with caution, in psychological and medical settings. In psychology, this methodology is frequently used to opt for the simplest description of the processes underlying a task.

Still, you have to be careful, because the lack of knowledge about the mechanisms and the lack of objective criteria about why one thought is simpler than another can provide an intuitive and biased approach to the subject.

In medicine, the razor is used in a heuristic procedure, that is, doctors and professionals must explain the patient's symptoms in the simplest way and thus achieve clinical reasoning under the bases of heuristics (concrete things).

Conclusions

As we have seen, Ockham's razor or the principle of parsimony is a principle that carries accompanying us for hundreds of years to simplify the tremendously complex world that we surrounds. To understand, in many cases, reducing is the first step, even though we omit essential information in this process. You can't start building a house from the roof, right?

Even so, despite all the uses we have seen for it, this principle cannot explain, far from it, all the events that occur on Earth. Complexity is also in its way the basis of modern society, therefore, not everything is reduced to "a single and simple explanation."

Bibliographic references:

• Hoffmann, R., Minkin, V. I., & Carpenter, B. K. (1997). Ockham’s razor and chemistry. International Journal for the Philosophy of Chemistry, 3, 3-28.
• Rodriguez-Fernández, J. (1999). Ockham's razor. Endeavor, 23 (3), 121-125.
• Kluge, A. G. (2005). What is the rationale for ‘Ockham’s razor’ (aka parsimony) in phylogenetic inference. Parsimony, Phylogeny, and Genomics. Oxford University Press, Oxford, 15-42.
• Ockham's Razor in Formulation, Starandpaint.com. Picked up on August 18 in https://starandinapaint.com/wp-content/uploads/2017/02/La-navaja-de-Ockham-en-la-formulacion_Inpra-16-4-2011.pdf
• The principle of parsimony in current cognitive science: Risks and solutions, Cienciacognitiva.org. Picked up on August 18 in http://www.cienciacognitiva.org/files/2013-10.pdf