Materials needed:

• Lesson plan (warm-ups, story, and game)
• Space for participants to form opposing groups

Description:

Before presenting participants with the thought experiment, engage them in at least one warm-up.

• For first time philosophers and/or for longer class periods, warm-up using the “Philosophy Warm-Up” prompts.
• If the group has already developed basic ideas about the nature of philosophy, use one or both of the “Identity Warm-Up” prompts.

All of these prompts can be discussed first in small groups and then debriefed as a whole group to prepare for the main thought experiment.

Before the main thought experiment, consider engaging children in a more focused warm up via the story of The Ship of Theseus (available in truncated form below or in are detail with this link); this can also make a good end point if this lesson is split into 2 classes.

Warm Ups: 

Philosophy Warm-up

• What do you think of when you hear the term “philosophy”?
• What does it mean to be a philosopher?

Identity Warm-up #1

• Write down something you know about yourself.
• Write down something you don’t know about yourself.
• Write down something pretty much everyone who knows you knows about you.
• Write down something hardly anyone who knows you knows about you.

Identity Warm-up #2:

• If you had to describe yourself using only 5 words, what would they be? Write them down.

As the conversation closes, tell participants to keep thinking about the identity-based warm ups as you shift to recounting the story of The Ship of Theseus (detailed below). This story might raise some of the following questions:

1. 1. At what point does the Ship of Theseus stop being the Ship of Theseus? Or does it remain the Ship of Theseus despite the replaced parts?
2. 2. On what basis does the identity of the Ship of Theseus rely upon: Who owns it? Who built it? What it symbolizes? Other?

The Ship of Theseus (Theseus’s Paradox):

In ancient Greece, there was a legendary king named Theseus who supposedly founded the city of Athens. Since he was a well-regarded king that fought many naval battles, the people of Athens dedicated a memorial in his honor by preserving his ship in the port. This “ship of Theseus” stayed there for hundreds of years, yet, as time went on, some of the wooden planks of Theseus’ ship started rotting away. To keep the ship nice and complete, the rotting planks were replaced with new planks made of the same material. At first, only a single plank need replacing. However, over the coming decades each piece was slowly replaced until non of the original material remained. Is it still the ship of Theseus?

After a bit of conversation around Ship of Theseus, consider introducing a personal parallel example in the form of the human body. Inform participants that a similar phenomenon occurs with our own physical bodies: “Within the span of seven years, every cell of your body will die and be replaced—you literally are not the same person you once were.” Some questions that might result from this include:

1. Where does our identity lie? Our body, mind, memories, and/or other?
2. In what ways are we different and in what ways do we remain the same over time?
3. Do we think about our bodies differently than Theseus’ Ship? Why or why not?

Once the conversations come to a close, bring all student back together and introduce round one of the game. Feel free to follow the script below and introduce your own variations so long as the core ideas remain consistent.

Mission to Mars / Staying Alive

Overarching Summary

There are three rounds. In each round, you will be presented with a scenario and then offered two choices. The decisions you make determine whether you stay alive or perish. You should always base your decisions on nothing more than the desire to keep yourself in existence; to stay alive – whatever that might mean to you. Also, each scenario should be taken at face value. The situation will be as described – there are no “tricks” – and you do not need to worry about other ‘what ifs’.

Round 1 – The Tele-transporter Choice

The Earth is about to implode. Scientists have figured out that there is only a month left before the internal gravity of the Earth sucks the entire planet into a space no larger than your fist. Scientists are 100% certain that everyone and everything on the planet at the time of implosion will perish. You have no choice but to leave Earth behind. We have enough resources to get everyone off the planet, you even have the luxury of deciding between two possible means of travel.

One method is tele-transportation. You will step into a scanner here on earth that will destroy your brain and body, while recording the exact state of all your cells. This information will be instantly transmitted to a replicator on Mars – taking mere seconds to arrive – which will then create a brain and body exactly like yours using entirely new materials. The person on Mars will look like you, think like you, in fact be indistinguishable from you. From your perspective, you simply walk into a pod on Earth, experience a bright flash of light and a cool sensation throughout your body, and when the light dims you are in a pod in the lab on Mars. This method is 100% reliable and you experience no pain.

The other method of transport is space travel. This choice is more risky – there is a 50% chance that the spacecraft will be struck by incoming debris and not complete the journey. There 50% chance that you will die in transit – floating in the cold vacuum of space. But if you do successfully take the spacecraft, then your body and brain won’t at any stage have been destroyed as is the case with taking the tele-transporter. This journey takes about 2 weeks.

You must choose the option you think will give yourself the biggest chance of surviving. How will you stay “alive”?

• If space allows, encourage/instruct students to move to one side of the room or the other based on the means of travel they chose. First, ask students from each side to first explain their rationales for the choice they made. Next, ask them how they might convince those on the other side to join their side. If students are indeed convinced, have them switch sides and explain how/why their thinking has changed. Move onto the next round once students have had a chance to explain their thinking.

Round 2 – Silicon or Virus?

Imagine now, for the sake of the next round, that everyone made it to Mars regardless of the decision they made (none of those who chose they spaceship died). However, there is a new problem…

Life on Mars turns out not as ideal as you may have first thought; two strange viruses have evolved on the planet which are causing a lot of problems. The first destroys your body parts. Fortunately, medical science is very advanced, which means people can simply be given artificial limbs and organs as required. These artificial limbs are indistinguishable from the organic parts you started with. You have been hit pretty hard by this virus and, in fact, almost your entire body is now made up of artificial parts, excluding you brain and other central organs.

However, there exists a second virus that attacks the brain. It is peculiarly nasty in that it doesn’t destroy the brain, rather it messes up the neural pathways, leading to a loss of memory and a seemingly random change in personality traits. One person who had the virus had been a successful author. Now he can’t write a word, but he’s become rather good at exotic dancing. Another person used to be very talkative and energetic, now they are shy and more reserved. (Insert other examples relevant to the context you find yourself in)

Unfortunately, you have caught this brain-changing virus. Medics can get around the virus by replacing pieces of the brain with advanced forms of silicon chip. In your case, they would have to do this to almost all of your brain. But trials show that you can be sure that the result will be the total preservation of your memories, personality, plans, beliefs and so on, and a person as able to carry on living a normal life with no noticeable changes to their personality. The alternative is to succumb to the virus with its consequent loss of memory and change in character.

You must make the choice which you think will give yourself the biggest chance of surviving. Do you let the virus run its course, or have your brain replaced by silicon chips?

• Have students move again and engage in another round of explanation and debate similar to the last round.

Round 3 – Die or Freeze?

The operation was successful, congratulations! What’s more, a few years later, advances in technology enabled scientists to perform a similar operation which gave you back an organic brain and body, so now you are a fully-organic human again.

Strange as it may seem, it has been discovered that reincarnation of a sort does actually occur. It seems that there is some immaterial part – call it a soul – in all human beings. On death, it leaves the body and enters the body of a new-born animal or human. It does not take your memories with, though it is thought that that it may have some effect in determining one’s character, but given the evidence for the strong influence of genes and upbringing, this effect is thought to be relatively small.

Even stranger than the fact of reincarnation, it seems that our souls die if stored at below freezing point for longer than a week. These facts are vital to the last choice you must make…

You are very ill, but scientists have almost found a cure for the disease you have, they expect to have a cure within the next 1-2 years. Further, they have also developed a technique to ‘deep freeze’ humans, enabling them to be revived later with their memories and character intact. You have two choices:

The first choice is to let the disease take its toll. Your body will die, but your soul will live on with no risk of fading away into nothingness.

The second choice is to be deep frozen, then thawed and cured later. This will destroy your soul and only has a 40% chance of success. There is a 60% per cent chance that the thawing and curing won’t work – that both your soul and body will die.

You must make the choice that you think will give yourself the biggest chance of surviving. Do you enter the deep freeze and ensure the death of your soul and a 60% change of bodily death, or let the illness take your life and allow your soul to pass onto another living being?

• Have students move again and engage in another round of explanation and debate similar to the last round.

Wrap up

To close out the activity, engage in a conversation about the thought experiment as a whole, encouraging students to share out their thoughts. Sample prompts include:

• Which round was the hardest/easiest to decide?
• What other factors might have impacted your decisions?
• What does it mean to be “alive” in each round?
• What makes you, you? (Continuity of body, mind, soul, and/or other?)