Mental experiments are one of the many tools we have created to understand and explain how the phenomena around us occur. Not only that, but they have been a very important pedagogical tool in the scientific area.

Moreover, because of their characteristics, they have been the object of debate both in philosophy and in the cognitive sciences, the natural sciences and pedagogy. But, what exactly do we mean by “mental experiments”?

What are mind experiments?

Mental experiments are hypothetical situations used to explain a situation or a phenomenon , through which would be the results, if the experiment actually occurred.

In other words, a mental experiment is a resource of the imagination (it consists of narrating a fictitious situation), which has enough logic to make it possible to imagine coherent results, so that these results allow us to explain something.

Gilbert & Reiner (2000) define mental experiments as experiments that have been mentally directed. That is, although there is no need to conduct them (and in many cases there is no real possibility of doing so either), they must include a hypothesis, objectives, results, with the aim of offering a series of logical conclusions about a phenomenon.

As a resource of the imagination, sometimes mental experiments are confused with analogical reasoning. However, the difference is that, while analogies are mainly characterized by making comparisons, mental experiments are characterized by posing a series of actions that are carried out in a figurative way.

Main uses in research

As we have said, mental experiments have arisen primarily from a specific intention or purpose: to understand how a phenomenon works, without the need to actually experiment with it.

However, from this same intention others have emerged, for example, that of justifying or refuting the legitimacy of a philosophical, mathematical, historical, economic or scientific model (especially they have been used in physical sciences).

In other words, mental experiments have three main uses: to explain, legitimize or refute explanatory models about the nature of a phenomenon. However, these two uses can be more specific according to the author who proposes them, or according to the theoretical and philosophical position that supports them.

For example, they have been widely used not only in the physical sciences but also in philosophy of mind and morals, in cognitive and computer sciences , and in formal education. That is why they have also been considered a model for teaching, that is, a teaching tool.

In contrast to these uses and functions, mental experiments have also faced some criticism. For example, there are those who consider that they are simply intuitions , and that as such, they cannot sustain sufficient rigour to be considered in terms of scientific knowledge or methodology.

3 examples of mental experiments

Since the 17th century we can find examples of mental experiments that have had a significant impact on our understanding of the world. Some of the most popular were conducted by Galileo, René Descartes, Newton or Leibniz.

More recently the role of mental experiments in the development of physics and quantum mechanics has been discussed , for example, through the Schrödinger’s Cat experiment. Likewise, the importance of mental experiments in the philosophy of language and the philosophy of the mind has been discussed, for example, with Searle’s Chinese room or the philosophical zombies.

1. Schrödinger’s cat

With this experiment, Schrödinger exposes how some principles of quantum theory collide with our most basic intuitions. It consists of the following: a cat is enclosed in a steel chamber , along with a counter that has a very small amount of radioactive substance.

There is a 50% chance that within one hour, one of the atoms will decay and poison the cat. There is also a 50% chance that none of the atoms will decay, which will keep the cat alive. So, the most logical thing is that if we open the steel box an hour later, we will find the cat alive or dead.

However, and this is what Schrödinger exposes as a paradox, following some principles of quantum mechanics, after one hour the cat would be both alive and dead at the same time. At least before opening the box, since for mechanics the states overlap until the moment when an external observer comes into play (it is this observer who modifies the states of things).

This experiment has gone through a number of very different and complex explanations, but in a very broad sense it has served to explain the counter-intuitive nature of quantum mechanics.

2. The Chinese room

With this experiment, the philosopher John Searle questioned the possibility of creating artificial intelligence that is not only capable of imitating the human mind, but actually reproduces it .

The hypothetical situation he posed was to imagine that an English-speaking person, who does not understand Chinese, enters a room where he is given an instruction manual written in English to manipulate some Chinese symbols in a certain order. Under this order, the symbols express a message in Chinese.

If, after manipulating them, you hand them over to an outside observer, he or she would probably think that the English-speaking person who does not understand Chinese does understand Chinese, even though he or she does not. For Searle, this is how computer operating systems work (imitating understanding but not achieving it).

3. Philosophical Zombies

Philosophical zombies are a fairly widespread concept in philosophy and whose antecedents we can trace in many theories. Nevertheless, it was David Chalmers who proposed the following mental experiment: if a world existed exactly like ours, but instead of being inhabited by human beings, it was inhabited by zombies, those zombies (who are physically identical to us) would still be unable to reproduce the human mind .

The reason: they do not have subjective experiences (qualia). For example, although they can scream, they do not experience joy or anger, so what Chalmers proposes is that the mind cannot be explained only in physical terms (as proposed by physicalism).

Bibliographic references:

  • Stanford Encyclopedia of Philosophy (2014). Thought Experiments. Retrieved May 3, 2018. Available at https://plato.stanford.edu/entries/thought-experiment/
  • Gilbert, J. & Reiner, M. (2010). Thought experiments in science education: potential and current realization. International Journal of Science Education, 22(3): 263-283.
  • Oliva, J. (2008). What professional knowledge should science teachers have about the use of analogies. Eureka Magazine Teaching and Dissemination of Science. 5(1): 15-28.