Mental experiments: what are they?

Mental experiments: what are they?

What are mental experiments? Let's read the following text: Mary is a brilliant scientist who is, for some reason, forced to investigate the world from a black and white room through the monitor of a black and white television. He specializes in the neurophysiology of vision and acquires, suppose, all the physical information there is to obtain about what happens when we see ripe tomatoes, or the sky, and uses terms such as "red", "blue", etc.

She discovers, for example, just what combination of sky waves stimulate the retina, and exactly how this produces through the nervous system the contraction of the vocal cords and the expulsion of air from the lungs that results in the pronunciation of the sentence " the sky is blue". … What will happen when Mary is released from her black and white room or given a television with a color monitor? Will you learn something or not?

With these words, the philosopher Fank Jackson wrote the mental experiment called "Mary's room". Through this experiment, it is intended to investigate whether Mary's experience is sufficient so that when she sees the world in color she is surprised or acts normally. That is, will Mary have learned so much that she will know what colors are like? Or as much as you have learned the lack of direct exposure will you learn new knowledge?

What are mental experiments?

Mental experiments are imaginative resources that are used to investigate certain aspects of nature and hypothetical situations.. Thanks to them, we can understand some aspect of reality without the need for direct experimentation. All are carried out at the mental level, that is, they lack empirical confirmations. Its applications, among them, range from philosophy, physics and mathematics.

Ornelas, Cíntora and Herández (2018) state about the mental experiments that "Our own ideas are at our disposal easier and immediately than the physical facts. We experiment with thinking, so say it, at a low cost. So it shouldn't surprise us that sometimes the mental experiment precedes and paves the way for the experiphysical mind ". The advantage of the mental experiment is obvious, since it does not require economic investment. However, are your conclusions always valid? Will it be necessary to empirically check your results?

Physicist and philosopher Ernst Mach spoke thus of mental experimentation: Those who make projects, those who build castles, romance and poets who get carried away by social or technical utopias, do mental experimentation; They are also made by the serious merchant, the thoughtful inventor and the wise. All diverse circumstances are represented and certain conjectures relate to these representations. But the former change in their imagination circumstances that are not in reality, or they represent these circumstances followed by consequences that have no links with them, while the merchant, the inventor and the wise have good representations of the facts as representations. and remain in their thoughts very close to reality.

Uses and criticisms

Mental experiments aim to explain, legitimize or contradict explanatory models about a phenomenon. The scope covers both philosophy, mathematics, history, economics and even psychology. They can be used as a form of experimentation or as a teaching tool. Experimenting and learning through thinking is a powerful teaching tool.

The main criticisms of this type of experimentation is precisely its lack of empirical evidence, so some authors describe them as simple intuitions. Thus, according to critics, mental experiments do not have the seriousness and validity necessary for their conclusions to be considered scientific knowledge.

Known Mental Experiments

The chinese room

The philosopher John Searle wanted to challenge the concept of artificial intelligence, how did he do it? Imagine that inside a room there is a person who only speaks English and is completely unaware of Chinese. Inside the room there are also Chinese letters and an instruction manual. Through a slit, someone who does speak Chinese, passes a sheet with questions in Chinese. The individual inside, through the instruction manual, is able to answer what they ask but without understanding anything.

Searle challenged other authors such as Alan Turing who said that if a machine can "cheat" a human and make him think he is talking to another human, it means the machine thinks. So that, Searle, through this mental experiment, wants to show that pretending to know Chinese is not understanding it, so it is not artificial intelligence.

Original position

John Rawls, proposed in 1971 this mental experiment on the theory of justice. A group of people must elaborate the laws of the future. Once these laws are composed, everyone will die. However, they will all be resurrected but without knowing if in the next life they will be rich or poor, men or women. So, what kind of laws will they create? What will they consider?

The author states that this mental experiment has two functions: on the one hand, it allows the principles of justice to be achieved and, on the other, the principles of justice must be examined. In this way, based on ignorance, that is, without knowing what they will be in the next life, all efforts will be combined to carry out fairer laws for all.


  • Aguilar, Y. and Romero, A. (2011). About mental experiments: an attempt to construct explanations in science. Scientific Magazine, 169-174.
  • Ornelas, J., Cíntora, A. and Herández, P. (2018). Tworking in the laboratory of the mind: nature and scope of mental experiments. Mexico: UASLP.