What is Laplace's Demon?

The search for certainty and the illusion of knowing what will happen tomorrow is something that has accompanied the philosophical reflections and scientific practices over time.

If we could be certain that tomorrow it will rain, or a war will break out, the decisions we would make today would surely be very different from those we would choose without knowledge from the future. Laplace's Demon is a character that represents all of this very well., where does it come from?

Laplace's Demon and the prediction problem

The illusion of predicting and controlling what surrounds us is a theme that we can find in a good part of scientific development. For example, classical mechanics was based on the idea that everything that exists in the universe and in nature can be know through mathematical logical reasoning, as well as through a geometric system to measure and predict what will happen.

In other words, class mechanics starts from considering that the universe and nature are governed by a series of initial laws that can be revealed by humans for modification.

For example, modern astronomy in the West, inaugurated by Newton, has this position as its antecedent.

Who was Pierre Laplace?

Pierre Laplace was a French astronomer, physicist, and mathematician who lived from 1749 to 1826.. He is credited with developing celestial mechanics, he worked alongside Isaac Newton and Galileo in predicting eclipses and discovering new planets. He also participated in the study of some gas molecules and atomic particles.

What Laplace suggested from his knowledge is that, through science, we can foresee and divine the activity of all behavioral systems that exist. And if not, the unpredictability would only be a knowledge error that, as such, can be corrected.

In Laplace's deterministic conception, everything can be predicted., and if it is not like that, it is because the knowledge produced by the human being has erred or is not enough.

What this means is that everything that exists in the universe is structured prior to and independently of the activity of human beings, with which our own actions and everything we are would be predetermined by the laws of the universe.

The deterministic demon (from Laplace)

Laplace's Demon is an imaginary character who has the ability to know the initial properties of all particles in the nature and the universe with such precision that he can apply natural laws to guess what will happen instantly or in a long time. time; from a precise movement to a work of art (Calabrese, 1999).

It is in other words, Laplace's Demon is a deterministic and all-powerful demon, a being that is outside the universe and that has predicted and decided everything that will happen in nature, including, of course, the activity of human beings.

The logic of prediction was transcendental not only in astronomy, the sciences of physics, mathematics, and natural sciences, but has been extended to the study of human behavior as well as its intervention.

For example, it has been present in the development of modern medicine, and we could even see how it impacted the traditional way of doing human sciences, as well as economic activity and financial. However, from the development of new scientific paradigms, Laplace's Demon has encountered some limits.

From determinism to indeterminism: the end of certainty

The logic of prediction was especially successful while the universe was understood in terms of linear systems, based on a stable cause-effect relationship. But when they arrived chaos theory and quantum mechanics to challenge the linearity of all systems, the scientific field also questioned the insistence on applying the logic of prediction to everything we know.

In very broad strokes and among other things, there was a paradigm shift from considering that in non-linear systems (which are complex systems, of chaotic and non-cyclical behaviors, as in human beings), the initial state is not equal to the final state nor does it determine it, with which, they are systems that cannot be be predicted.

In the field of science, the universe and nature in general are no longer conceived as a set of laws of general coverage, pre-established by an external being. This is how from the beginning of the 20th century, there is an important turn where it is considered that, although it is possible to calculate probabilities, there can always be prediction failures. From this, some authors consider that an era marked by the end of certainty is inaugurating, especially in the human and social sciences.

Bibliographic references:

• Trainini, J. (2003). Towards the need for a new medical paradigm. Argentine Journal of Cardiology, 71(6): 439-445.
• Calabrese, J. L. (1999). Expanding the frontiers of reductionism. Deduction and nonlinear systems. Psychoanalysis APdeBA, XXI (3): 431-453.
• Wallerstein, IM (1999). The social sciences and the humanities on the threshold of the 21st century. The end of certainty in the social sciences. UNAM: Mexico.