Last time I introduced a paradox about Achilles and the turtle, and it was very hotly discussed, so today I will share a brain-burning thought experiment, the ship of Theseus.
<h1 class="pgc-h-arrow-right" data-track="162" > the paradox of Theseus' ship</h1>
This thought experiment was first proposed by the Greek philosopher Plutarch. Theseus was the great hero of ancient Greece, and the Athenians left the ship he took when he returned from Crete as a memorial. As time passed, the planks on the ship began to decay, and the Athenians removed the broken planks and replaced them with new ones. Over time, every plank of the ship was changed.
So the question is, is the ship after the replacement plank still the ship of Theseus before? (For the sake of convenience and the distinction behind, we call it Boat A)
If it is the same ship, what do it have in common with the original ship? If it is not the same ship, then when did it start to stop being the original ship, when the first planks were replaced, or after all the planks were replaced?
In ancient Greece, Heraclitus, Socrates, and Plato all discussed similar issues. For example, Heraclitus famously said: One cannot step into the same river twice. In his opinion, the river has been flowing, and the river in the river that has been stepped into twice must have changed, so that the river that has been stepped into twice is no longer the same river.
Although Heraclitus's starting point is the theory of the change of life and death of "everything changes and nothing is permanent", it also raises the same question as the ship of Theseus: how to define the identity of matter, whether matter belongs to the same substance in different states at different times and in different spaces, and what are the criteria for defining it?
In modern times, the British philosophers Hobbes and Locke also discussed this problem separately, and raised many variant problems, such as Locke's socks and his grandfather's short-handled axe.
Locke's socks, said that Locke has a pair of socks, worn for a long time there are holes, so he used cloth to put a patch on the socks, and then more and more patches, and finally the original socks are broken, the whole socks are composed of patches of different colors and fabrics, so at this time this sock is still the previous socks? Grandfather's short-handled axe is a similar scene and problem, which is repeated here.
It is worth mentioning that Hobbes expanded on the problem of the ship of Theseus, which is very interesting: if a new ship is rebuilt from the old planks taken from the ship of Theseus, we call it ship B. So which of the two ships is the real Ship of Theseus?
From this we can ask the question: What is the basis for keeping things unchanged? Is it a form or a constituent element?
John. Locke
<h1 class="pgc-h-arrow-right" Data-track="103" > components are fundamental? </h1>
If the constituent elements are regarded as the root of things, then the ship A that has been replaced with wooden planks is not the same ship as the original ship of Theseus, so can it be said that ship B, which was rebuilt with the original old wooden planks, became the ship of Theseus?
Obviously this is not the case, because there is a problem of quantitative change here.
If the constituent elements are fundamental to determining the identity of matter, then the ship of Theseus is no longer the original ship when the first plank is replaced, even after a little wear.
By extension, everything is constantly changing and depleting, so is there no question of material identity and continuity?
In the case of the human body, our bodies are made up of elementary particles. From the day we were born, we continued to undergo metabolism all the time, and the rate of metabolism was much faster than most of us think. The particles that make up your body today are very different from yesterday, and even more so than they were a dozen years ago.
So when all the particles are replaced, are you still you? For example, if you lost a leg due to an accident, are you still you?
Or, on the other hand, if I take apart all the materials of a table and reassemble them into a bed without missing a beat, and the two elements are identical, is this bed the original table? Apparently not either.
Therefore, no matter from the perspective of both positive and negative points of view, the constituent elements of matter (no matter how subdivided) cannot be used as the criterion for the invariance of matter.
So, what exactly is it?
<h1 class="pgc-h-arrow-right" data-track="161" > Aristotle's formal cause</h1>
Aristotle believed that this problem could be solved by describing the four causes of an object. The materials that make up matter are material causes, the design and form of matter are form causes, and form factors determine the nature of objects. Based on the formal cause, the ship of Theseus is still the original ship, because although the material has changed, the form of the ship has not changed, so no matter how the wooden planks are replaced, the ship is still the original ship of Theseus. In the same way, no matter how much a person's metabolism, he is always himself, not someone else.
Aristotle
From the perspective of our daily habits, this statement is indeed more reliable, so is the formal cause the key to ensuring the continuity of matter?
In my opinion, this is not the case, Aristotle's definition of formal causes is more general, it is the style or concept to be presented by the material, which belongs to the definition of the philosophical category, and has little significance for the definition of practical things.
For example, if, by replacing the planks, I enlarge the ship a lot, or add many new parts, so that I don't even know its mother, according to the four causes, the form of the ship is changed, that is, the form is changed, then whether it still belongs to the original ship.
If the same person becomes physically disabled or has been reshaped, is he still the same person? At the extreme, his consciousness enters a machine, is he still himself?
Is it obviously inappropriate to judge the immutability of matter solely on the basis of formal invariance?
Does this mean that matter does not exist as one and continuous?
You may say that if it does not exist, it does not exist, and whether there is any impact, it is nothing more than a language game for philosophers.
That would be a big mistake.
<h1 class="pgc-h-arrow-right" data-track="163" > absurd claim of innocence</h1>
For a simple example, Zhang San and Li Si borrowed twenty thousand yuan, and two years later Zhang San asked Li Si to repay the money, and Li Si said: It was me who borrowed the money two years ago, and now my body has changed, and my appearance has changed a lot, and I am no longer the one I was two years ago, so I don't need to pay you back.
Zhang San said: This is sophistry, no matter how you change, it is still yourself. Even if your body changes, you still have the mind and the soul, which is unchanged.
Li Si said: Wrong, my mind and soul have changed even more in the past two years, my values have changed, and my personality has changed a lot, otherwise how can it be so shameless?
Zhang San had nothing to say and stabbed Li Si to death with a knife.
Half a year later, Zhang San was arrested, the judge pronounced Zhang San's guilt, Zhang San said unconvincedly: Whether my body or my mind has changed a lot in the past six months, I am no longer the person I was half a year ago, the murderer was not me at that time, I was not at this time, you can't convict me.
So how does the judge decide? Obviously, Zhang San could not escape punishment for such a reason, even if Zhang San fled for ten years and changed more, he still had to bear the corresponding legal responsibility. It can be seen that in real life, we must find an unchangeable standard for the identity of things, otherwise many things will become chaotic.
So what is this criterion? I think it is neither a constituent element nor a mere form, but a "concept".
<h1 class="pgc-h-arrow-right" data-track="164" > the concept behind things</h1>
The concept here is not just a simple naming, for example, this ship is called "The Ship of Theseus", and his name is "Zhang San". It is an abstract generalization of the various properties of matter.
Let's take Apple as an example. From the beginning of Apple's founding, whether it is leaders, employees, office locations or employees, it has changed a lot, but no matter how it changes, as long as it does not go bankrupt, it will always be Apple.
"Apple (whether the name changes or not)" here is the concept of this high-tech company, which is a high-level generalization of all the attributes of the high-tech company's personnel, products, architecture, ideas, etc., and is an abstract whole in which all attributes are combined. This abstract whole does not change with the change of attributes, and is the fundamental reason why the company remains unchanged.
Plato
What about real things, I think there is something similar to Plato's ideas. Plato believed that all the things we perceive are appearances of unreal changes, and behind these appearances there is a world of ideas, and that the things in this world of ideas are real and unchanging.
I think it is this idea that determines the immutable nature of things, and the difference of course is that this idea is not what Plato thought actually existed, but an abstract generalization of the characteristics of matter.
For example, the decision that the ship of Theseus is what it is an idea behind it, this idea is an abstract generalization of its constituent elements, forms, functions, and purposes, it is the basis for determining the identity of things, and the elements and formal causes mentioned above are the attributes of this idea, and these attributes do not change no matter how they change, its idea does not change. So no matter how the ship of Theseus changes, it is always itself, even if it is tattered and rotten into mud.
Of course, this kind of concept is more of a philosophical hypothesis, and it is difficult to explain the problem in real life. So how to judge the identity of a thing in a real life scene?
<h1 class="pgc-h-arrow-right" data-track="165" > criterion for judging the identity of people and things</h1>
I think things should be treated in two categories:
One is the unconscious substance, such as the Ship of Theseus and the Apple mentioned above, which have only a monistic property of matter (extension), guaranteeing their identity only concerned with change and continuity at the material level:
1. The form of the substance is unchanged, that is, the overall structure of the substance has not undergone major changes, for example, although the wooden planks of this ship have been continuously replaced, their overall structure has not changed;
2. There is continuity in space-time, that is, the existence and change of matter in space and time is continuous and uninterrupted, so that the new ship that was reconstructed with old wooden planks, as Hobbes said, no longer belongs to the original ship.
The other category is conscious things, mainly refers to people, this kind of things have the duality of matter (extended) and consciousness (mind), so before judging whether there is identity in the air at different times, it is also necessary to determine whether a person is conscious or physical.
This question is easier to answer than the identity of matter, and we can illustrate it with a simple example.
We often see two people swapping bodies because of some coincidence in some film and television dramas, Zhang San's consciousness occupies Li Si's body, Li Si's body occupies Zhang San's body, then at this time, Li Si's body with Zhang San's consciousness is Zhang San or Li Si, this question must not be too controversial, although Zhang San's body is completely different at this time, but as long as his consciousness is still Zhang San's consciousness, then he is Zhang San.
In the same way, if we somehow transfer Zhang San's consciousness into a supercomputer, even if the computer is no longer a person in biology, it is still Zhang San.
Thus it is the consciousness, not the body, that determines what a person is.
Based on this, the problem of guaranteeing a person's continuous identity in different time and space is equivalent to the problem of continuous identity of consciousness, without considering physical factors.
My personal opinion should have two points:
The first is continuity, the uninterrupted and cognitive continuity of consciousness in time and space, including the continuity of memory, personality, values, knowledge, emotions, and so on.
If there is a technique that we do not yet understand, which completely copies a person's consciousness and uploads it to another identical body, which one is him? In this case, I think that the copied consciousness already belongs to another person, because the consciousness belongs to the flow and change, and the two pieces of consciousness may be exactly the same at the moment of copying, but the moment they are copied, the two pieces of consciousness are divergent due to the influence of various factors, and they belong to two completely different subjects.
Therefore, in summary, compared with other things, human beings cannot be generalized due to the existence of consciousness. Consciousness plays a decisive role in judging the continuity of things.
Of course, in the two thousand years since the paradox of the "Ship of Theseus" was proposed, many philosophers have proposed different answers, but there is no answer that convinces everyone, and I certainly do not dare to compare with these sages. (End)