Plank of Carneades

What is the Plank of Carneades?

The Plank of Carneades is a thought-provoking challenge about making tough choices when it comes to right and wrong. Imagine that two sailors have survived a shipwreck and are stuck out in the ocean with only one piece of wood, or plank, to keep them afloat. The problem is, the plank is only big enough for one person. If both of them try to use it, they’ll both drown. But if one sailor grabs the plank and saves himself, he could be seen as letting the other sailor die. This scenario was introduced by an ancient Greek thinker named Carneades to stir up questions about fairness and what we should do in super tough situations.

Here’s another way to look at it: The Plank of Carneades is like a puzzle without a clear solution, intended to make us scratch our heads about what’s fair when life is on the line. It was dreamed up by Carneades, who doubted that there were set-in-stone rules for what’s right and what’s wrong. He used the story of the two sailors and the single-use plank to show that sometimes, what’s fair or just might change depending on the situation, especially when people’s lives are at risk.


Carneades created this scenario to question a belief by the Stoics, who thought there were concrete rules for justice. In the story of the plank, he makes us think about the idea that what is morally okay could depend on what’s happening at the moment. It’s a great example of when the usual rules for right and wrong might not seem so clear.

Key Arguments

  • Survival – The first sailor might say that wanting to stay alive is natural, and grabbing the plank for himself is just trying to live. It’s something most living creatures want to do.
  • Justice – The other sailor could argue that he should have an equal shot at using the plank, and it wouldn’t be fair if the first sailor took his chance away.
  • Moral Relativity – The thinker Carneades might say what looks fair in one case, might not look fair in another. It depends a lot on what’s happening at that time and what the stakes are.
  • Conflict of Rights – There’s a big clash between the sailors’ rights to stay alive. It brings up tough questions about whose right is stronger, or if there’s any way to find a balance.
  • Practical Decision-Making – This situation makes it clear how hard it can be to make choices about what’s moral and what’s not when the choice could mean life or death.

Answer or Resolution

The Plank of Carneades doesn’t give us a neat answer because it’s really about getting us to talk and think about how we make moral choices. Some people might think we should just focus on what happens as a result, others might lean on ethical rules, and some might say it should be left to chance, like flipping a coin. Today, philosophers use this story to talk about fairness and to show how our ethical choices are often influenced by our own personal views and the situation we’re in.

Major Criticism

Some people think this story is too out there to help with everyday problems about what’s right and wrong. These critics say it’s not helpful because it’s about a situation that probably won’t happen. They also think it makes things too simple by forcing us to choose between just two options, without thinking about other ways to solve the problem.

Others say the story doesn’t consider the sailors’ reasons for their actions or their character. It just assumes they’ll both act out of their own interest and doesn’t think about other things humans do, like sacrificing for others or working together.

Practical Applications

This isn’t just a story for philosophers to sit and ponder. It has real uses in the real world, like these:

  • Law: When lawyers and courts deal with life-or-death problems, like figuring out who’s to blame in an accident, they can think back to the plank story to help sort out responsibility.
  • Medical Ethics: Doctors sometimes face hard decisions about things like who gets an organ transplant that can save their life. It’s like deciding who gets the plank.
  • Business Ethics: Companies might have to make cuts to stay afloat. Deciding who gets let go can remind us of the two sailors and the single plank.
  • Military Ethics: The military can face situations where they have to decide if some soldiers should be risked to save others. It’s a tough call similar to the plank dilemma.

In these situations, the Plank of Carneades makes us think over how we make decisions that involve tough moral choices, especially when lives are at stake.

Related Topics

  • Utilitarianism: This is a belief in doing what causes the most happiness for the most people. It relates to the plank story because it emphasizes outcomes over strict rules of right and wrong.
  • Trolley Problem: Another famous thought experiment where you have to decide if you should take action that will save multiple lives but end one. Like the plank dilemma, it’s about choosing in a no-win situation.
  • Moral Absolutism vs. Moral Relativism: These are two sides of a debate about if there are universal moral truths or if what’s right or wrong changes based on the circumstances, like what Carneades suggested with the plank.
  • Social Contract Theory: This is about the deal we have with society to follow its rules in exchange for protections, but what happens when these rules lead to a problem like the one in the plank story?


The Plank of Carneades takes us into deep waters of ethics and challenges us to imagine what we’d do when life is on the line. While the story doesn’t give us the answers, it’s useful for stirring debate and helping us sharpen our views on fairness. It teaches us that sometimes, rules can be bent depending on the situation, and it’s not always black and white. This thought experiment is still useful for making us think differently about our choices today and reminds us that understanding why we decide things is just as important as the decisions themselves.