Heraclitus (c. 535 – c. 475 BC) was an Ionian philosopher born in the city of Ephesus. Ephesus was on the coast of modern day Turkey but was at the time part of the Persian Empire.
Is the ship of Theseus the same, even after every part of it has been replaced?
The ship wherein Theseus and the youth of Athens returned from Crete had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their places, insomuch that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same.
— Plutarch, TheseusThings seem to be constantly changing. Heraclitus thought everything must be in a permanent state of flux, or change - flipping from one opposite to the other: Day, for instance, changes into night, which in turn changes back again to day.
You can never step into the same river twice.
Yet, despite everything constantly changing, we recognise things as being the same! How can this be? How can the river be the same and different at the same time? How can you be the same person, but different at the same time?
You could think of it like this: The water that makes up the river is different, but the meaning of the name ‘the river’ is, in a sense, the same.
Heraclitus explained this with the concept of Logos. Logos means word, or reason, or meaning.
(Lots of words come from Logos: dialogue, legal, legacy, lesson, anthology, apology, college, decalogue, logic, biology, sociology, logo, analogy.)
But what is Logos? For Heraclitus, Logos was divine - like a god. It governed the universe. Heraclitus considers the logos to be a universal, cosmic law, according to which all things come into being, and by which all the material elements of the universe are held in balance.
This logos holds always but humans always prove unable to ever understand it, both before hearing it and when they have first heard it. For though all things come to be in accordance with this logos, humans are like the inexperienced when they experience such words and deeds as I set out, distinguishing each in accordance with its nature and saying how it is.
The road up and the road down are the same.
Explain the Ship of Theseus thought experiment. What is the question that it raises?
Why did Heraclitus think that everything was in a permanent state of change or flux? What did he famously say about a river to illustrate this?
How did Heraclitus explain the fact that we recognise things as being the same?
Explain, in your own words, what you think Logos means. (Lots of different philosophers have thought that it means very different things, so just try to explain what you think it means.)
What do you think Heraclitus meant when he wrote, ‘the road up and the road down are the same’?
What do you think of Heraclitus’ account? Do you agree that everything is changing? Do you agree that we are able to identify things because of Logos?