Duplicate this page before you start, and write all your answers in your own copy.

Working on your own today. Your teacher is away, so this page runs the lesson. Work through it from top to bottom, on your own, and write every answer in your own copy. There are three videos, so you will need headphones. Where the class needs to pool its answers, the page tells you how. Where a box says "Open this after…", answer first and open it second.

<aside> 📝

Why this lesson matters for your essay. Two of the six titles for your own exam session, May 2027, ask about exactly the kind of knowledge you will look at today.

Title 3: In the production of knowledge, how can knowledge be reliable if it is built on assumptions? Discuss with reference to the human sciences and one other area of knowledge.

Title 5: In the production of knowledge, when choosing one explanation over another, to what extent should simplicity be prioritized? Discuss with reference to two areas of knowledge.

Nothing on this page answers either title. But every case today is real, named and dated: the kind of evidence an essay needs. Look out for the 📌 marks, which show where a case connects to one of these titles. At the end, you will decide what the cases let you say.

</aside>

🪙 1. Ten francs

Last lesson asked whether a result about people still holds when someone else, somewhere else, tests it again. Today goes one step further back. Before the human sciences can study people at all, they have to take some things about people for granted. What are those things, and what happens when they are not true?

Start with a game.

Imagine that you and one other person in this room, chosen at random, are given 10 francs between you, in one-franc coins. One of you, the proposer, decides how to split the money. The other, the responder, sees the offer and decides. If the responder accepts, you both keep the split. If the responder rejects, you both get nothing. You play once, you cannot talk, and you never find out who the other person was. You will play both parts.

✍️ Write here, on your own. Do not talk, and do not look at anyone else's answers.

1. You are the proposer. How many of the 10 francs do you offer the responder?

2. You are the responder. What is the smallest offer you would accept? Anything below it, you reject.

3. In one sentence each, why did you choose those two numbers?

When everyone has finished, pool the class's answers like this. Do not read on until the table below is filled in.

1. Everyone writes their two numbers on a small piece of paper, with no name: the offer first, then the smallest offer they would accept.
2. One volunteer collects the papers, shuffles them, and writes the two lists of numbers on the board.
3. Everyone fills in the table from the board. To find the middle offer, put all the offers in order from smallest to largest and take the one in the middle; if there is an even number, take halfway between the two middle ones. A responder would reject 1 franc if the smallest offer they would accept is more than 1.

✍️ Write here: the class results.

🧮 2. The perfectly selfish player