The Ephesian School of philosophy is centered around the ideas of a prominent philosopher from Greece - Heraclitus of Ephesus (hence the name). He argued that everything in the universe is ever-changing, just like fire. Heraclitus is also the author of a very famous saying that one man cannot enter the same river two times. Basically, this statement represents the ideas of the Ephesian school in a nutshell.

It is a fact that the Ephesian School was not official. However, this doesn’t deprive it of having the loyal followers. As Diogenes Laлrtius mentions that the people who supported and shared these ideas called themselves "Heracliteans." Even Plato describes Cratylus in his dialogue as a disciple of Heraclitus.

The Heraclitus of Ephesus (ca. 544-480 BC) came from the family of the Ephesians and was to inherit power, but gave way to the throne to his brother. At the end of his life, he completely left Ephesus and lived for some time in the mountains, eating grass and roots, but soon fell ill and died. The teaching of Heraclitus is not only one of the examples of ancient Greek philosophy, but also a remarkable example of ancient Greek dialectics.

Today, researchers, unfortunately, do not have any works of Heraclitus. It is known that a work under the general title On Nature belonged to him. The work was divided into three parts: "On the Universe", "On the State", "On the deity". By definition of Aristotle, Heraclitus belonged to the so-called first "philosophers of nature" - natural philosophers, or "physiologists". It is clear that the questions of natural philosophy make up the heart of the inheritance of the philosopher.

The most important linking factor of the Milesians with Heraclitus is the naturalistic principle of explaining the phenomena of reality from the spontaneous material element - water, apeiron, air, fire. Fire, a contradictory entity that is constantly changing and flowing, is Heraclitus’s element. The cosmos in general and all that is in it the philosopher announces as the modification of the primordial, as a result of its condensation and dilution (in common with the Milesians, the means of explaining the origin of things).

At the same time, with the physiological orientation of the doctrine, Heraclitus gives the fire the life-giving power. The fire enhances "the soul" in all the things that arise from it, in such a way that the entire Cosmos appears as an animated reality.

The doctrine of the Logos has the same significance for the philosophy of Heraclitus as the doctrine of the Fire. Most researchers agree that it was Heraclitus who used this word as a philosophical term. By definition, the Logos is an indissoluble, unchanging law, a regularity, or a measure of volatility and changeable things.

Heraclitus was the author of an extremely controversial concept that is quite difficult to grasp. He argued that the opposite things are in fact identical. Everything in the universe is and is not at the same time. Namely, no matter what’s going on with the water in the river, but the river itself stays the same.