ATOMISM: HISTORY, THEORY, POSTULATES AND REPRESENTATIVES - HISTORY - 2025

The atomism is a theory that all reality and objects in the universe are composed of very small particles, which are inseparable and unbreakable and are called atoms. Atom means something uncut or that cannot be divided. The word atom comes from the sum of two Greek words: a, which means without, and tomon, which means cut.

The atomistic school began as a philosophical movement in very ancient cultures of Greece, Rome and India. Leucippus and Democritus founded the movement around the 5th century BC.

John Dalton, creator of atomic theory and its postulates. Source: Joseph Allen, via Wikimedia Commons.

In its beginnings, the atomist school was based on the philosophical aspect and lacked evidence, which prevented it from adding followers. The theory was abandoned for several centuries and only became more widely accepted in the early nineteenth century, thanks to chemical evidence of its postulates.

The objective of the first representatives of atomism was not to talk about the structure of things, but to explain how they changed or remained the same. For the early atomists, atoms always endured; and when there was any change it was because the atoms were combining.

There are several types of atomistic beliefs. The traditional one affirmed that the objects are the set of atoms and that between these there is only emptiness. It can be said that it is a variant of philosophical materialism, since it ensures that the intangible does not exist. Also present is social atomism, the cosmological or physical, the logical, the social, the biological, and the psychological.

Origin and history

The atomistic school was born in Ancient Greece as a philosophical theory dating back more than 2500 years. In India too, ideas about atomism were developed very early in history. Buddhist philosophers, the Jainas, and even the Hindus wrote in ancient times about atomism.

The first philosopher in India to formulate ideas about the atom was Kanada. In India it was believed that there were four types of elemental atoms. These in turn had more than 20 qualities and could be combined with each other. The philosophers in the Asian country delved into how they were combined, how they reacted and the possibilities that existed to split an atom.

In Western culture, atomism is associated with the pre-Socrates era. Leucippus and Democritus are considered the founders of this current, although Aristotle gives all the credit for the invention of atomism to Leucippus. It was Aristotle himself who led the first movement with ideas that moved away from atomism.

In the 16th and 17th centuries, interest in atomism was reborn thanks to the scientific advances of Nicolás Copernicus and Galileo Galilei. In the 18th century the first mathematical theory of atomism was created, using principles of Newtonian mechanics.

It was only in the 19th century that an atomic theory was developed. John Dalton proposed that each chemical element is made up of atoms of a unique type, which can combine to form other structures.

Philosophical atomism led to the development of atomic theory, but modern science was responsible for refining the theory. Atoms were shown to be made up of smaller particles (electrons, neutrons, and protons). These in turn are made up of even smaller particles called quarks.

Theory of atomism and postulates

The theory of atomism was developed in 1803 at a scientific level, stating that matter is composed of basic and indivisible units that come together to form different compounds.

The atom was believed to represent the smallest unit of matter, and more than a hundred varieties of them have now been discovered. Each type of atom is called by the name of a chemical element.

Although the Englishman John Dalton, a naturopath and chemist, started from the concepts of the atom of the ancient philosophers, he varied the meaning of the word somewhat. Dalton, for example, did not share the belief that matter had to do with a single substance, but that there were atoms with varied characteristics and of different types.

He was also responsible for implementing the periodic table of elements and for establishing hydrogen as the lightest element, and therefore as the basic standard when studying each element.

The theory of atomism helped establish the foundations of today's chemistry. Although it has been revised over the years, the basic assumption that the atom is the smallest unit of matter is still valid.

Advances have shown that Dalton called what are now known as molecules compound atoms, that atoms can be modified by fusion, and that they are made up of smaller structures.

Postulates of Dalton's atomic theory

To better explain how matter was made up, Dalton developed some postulates or principles. These postulates were accepted for most of the 19th century, but further experiments proved that some of them were not correct.

1-All matter is made up or composed of inseparable particles that are called atoms.

2-Atoms of the same element are similar in shape and weight, but are different from atoms of other elements.

3-Atoms cannot be created or generated and neither can they be destroyed.

4-Compound atoms can be formed when the atoms of different elements combine with each other.

5-Atoms of the same element can combine in more than one way to form two or more compound atoms.

6-The atom is the smallest unit of matter that can participate in a chemical reaction.

From these postulates, it has already been shown that the one who speaks of the concept of the indivisibility of the atom affirms something wrong, since it can be subdivided into protons, neutrons and electrons. The second postulate has also been corrected, since the atoms of some elements vary in their masses or densities and are known as isotopes.

Representatives

Leucippus and Democritus are the two philosophers of antiquity who have been considered the founders of the atomistic school, and therefore are the most important representatives. There is no agreement on which of the two was the creator or what each contributed to atomism, although Aristotle gives all the credit to Leucippus, Democritus' teacher.

What is known about the ideas of Leucippus and Democritus has endured over time through the writings of other scholars such as Aristotle, Diogenes, or Theophrastus, among others.

Plato was one of the first voices to oppose atomism, since he argued that atoms that collide with other atoms cannot produce the beauty and shape of the world. Instead, Plato posited the existence of four elements: fire, air, water, and earth.

Aristotle in turn affirmed that these four elements were not made of atoms and that the existence of a vacuum, as atomism affirmed, violated physical principles. Aristotle was the first representative of a movement that moved away from the ideas of the atomist school.

Later appeared Epicurus, also called Epicurus of Samos, a Greek philosopher who defined himself as a follower of Democritus' atomism. He questioned how natural phenomena (earthquakes, lightning, comets) could be explained with Aristotle's theory.

Figures in modern times

Interest in atomism re-emerged in the 16th and 17th centuries. Nicolás Copernicus and Galileo Galilei were converted to atomism by some scientific advances that began to contradict some Aristotelian theories that were dominant at the time.

Other philosophers, such as the English Francis Bacon, Thomas Hobbes, and Giordano Bruno were considered atomists for some time. However, most of the recognition of the rebirth of the atomist school goes to the French René Descartes and Pierre Gassendi.

Descartes claimed that everything physical in the universe is made up of small corpuscles of matter; and that sensations, such as taste and temperature, are caused by the shape and size of these small pieces of matter. This idea of ​​Descartes had many similarities with atomism, although for Descartes there could not be a vacuum.

Then Roger Boscovich was in charge of, in the 18th century, creating the first mathematical theory of atomism. Finally, it was John Dalton who developed the atomic theory and its postulates.

He proposed for the first time that each chemical element is composed of atoms of a unique type and that they can be combined, forming new, more complex structures.

References

1. Atomism. Recovered from encyclopedia.com
2. Atomism - By Branch / Doctrine - The Basics of Philosophy. Recovered from philosophybasics.com
3. Berryman, S. (2005). Ancient Atomism. Recovered from plato.stanford.edu
4. Garrett, J. (2003). The Atomism of Democritus. Recovered from people.wku.edu
5. Pyle, A. (1997). Atomism and its critics. Bristol: Thoemmes.