Today, the word "quintessence" most often means the main essence of any phenomenon, its main meaning. But once this term had a slightly different meaning.
Translated from Latin, the word quintessence literally means "the fifth essence." In relation to what it was "fifth", one can understand if we recall the idea of the world that existed in ancient philosophy.
Quintessence in ancient philosophy
The ancient Greek philosopher Empedocles became the founder of the idea of four elements that form everything that exists in the world. These elements are water, earth, air and fire. All differences between plants, animals and other objects are explained by the ratio of elements. This idea became generally accepted in ancient philosophy. Aristotle also adhered to it, but he decided to supplement the teachings of Empedocles.
According to Aristotle, along with the four main elements, there is a fifth one, which is fundamentally different from them. It is the most subtle and perfect, it is eternal, i.e. does not arise and cannot be destroyed, the stars and the sky outside the lunar orbit are made of it. This element Aristotle called the ether or "the fifth essence" and this is how the term "quintessence" appeared.
Already among ancient philosophers, the idea of quintessence met with criticism. Some of them believed that there was no need to admit the existence of any additional element to explain, for example, the nature of stars, if we assume that they are composed of fire. The philosopher Xenarch's treatise is called “Against the Quintessence”. And yet the idea stuck.
Quintessence in the philosophy of the Renaissance and modern times
The ideas of ancient philosophy were inherited by the Middle Ages, and especially the Renaissance. Agrippa Nettesheim, G. Bruno, F. Bacon and some other philosophers of the Renaissance and the beginning of modern times consider the quintessence to be the connecting link between the mortal, the material body and the immortal soul. The astral body, which has both material and non-material nature, consists of it.
The idea of quintessence was so popular in those days that F. Rable, in his novel "Gargantua and Pantagruel", even sneers about this, mentioning a certain "extractor of quintessence".
The idea of quintessence in alchemy was of great importance. She was presented as the basic element of all existence, which was extracted by God himself. Some thinkers - for example, Theophrastus Paracelsus - identified the mysterious "fifth essence" with … man! This approach is fully consistent with the philosophy of humanism, which proclaimed man "the measure of all things."
Surprisingly, the concept of quintessence also exists in modern physics. This is the name given to one of the concepts of dark energy - a mysterious entity that could explain the expansion of the universe.