Week 15 Philosophy Workshop: The Lighthouse Keeper's Stair

Part 1 — The Big Picture

This week you learned Sartre's claim that existence precedes essence, Camus' absurd and Sisyphus imagined happy, Beauvoir on freedom in a situation, the 3 answers to the question of life's meaning, and the 6 steps of a reasoned position. In this last workshop you take one illustrative packet about a lighthouse keeper who climbs the same stairs every night. You reconstruct four short arguments and key each for validity. Then you test a variation of Sisyphus, the harbor, where the lamp no longer guides any ship, and ask whether the keeper's life can still be meaningful. You write a short dialogue between a defender of meaning created by the individual and a defender of meaning found in valuable activities, each in their strongest form. Last, you check a chatbot's version of the same work and correct its slips by hand, starting with whose words, if any, the course actually pins.

Time budget: Plan for about 90 minutes.

Part 2 — The Task

Guiding question: Which of the lighthouse packet's four arguments are valid, which one runs a conditional backward, can the keeper's life be meaningful once the lamp guides no one, and where exactly do the created view and the found view part over the harbor variation?

Workshop data: Lighthouse packet: four illustrative arguments and one thought-experiment variation on Sisyphus and his rock

Source: An illustrative packet of four short arguments and one thought-experiment variation written for this course's workshop; it describes no real lighthouse or person, and its premises are written for teaching, not claims the course endorses.

• Rows: 4 arguments (A1 to A4) and 1 thought-experiment variation; the reconstruction table has 4 rows, the count table has 3, and the variation table has 4
• Arguments: A1 the task that never finishes; A2 the purpose from outside; A3 the task found worth doing; A4 the absurd and despair
• Thought-experiment variation: the harbor variation, labelled as a variation on the shape of Sisyphus and his rock from Camus, The Myth of Sisyphus

Part 3 — Materials & Procedure

Tools and materials

• A free word processor or note-taking app for arguments in standard form and short dialogues, with the pinned public-domain texts on Project Gutenberg and the Internet Classics Archive open beside it; and one approved chatbot used as a sparring partner whose reconstructions, quotations, and attributions the student checks word for word against the pinned text and record before trusting them
• A free word processor or note-taking app
• One approved chatbot

Ways of working

• reconstruct-the-argument
• test-the-thought-experiment
• write-the-dialogue

Procedure

1. Read the lighthouse packet in Part 2 twice. In your notes, copy each of A1 to A4 into standard form: number the premises P1 and P2, and write the conclusion last as C, introduced by So. Tool: A free word processor or note-taking app. Check: Four reconstructions, each with numbered premises and one conclusion line that begins with So.
2. In the first table, name the form of each argument and write valid or invalid with a one-sentence reason that uses the definition of validity. Then name the premise a defender of another answer about meaning would reject, without calling any argument sound or unsound. Tool: A free word processor or note-taking app. Check: Every row of the first table has a form, a key, a reason, and a rejected premise; no row says sound or unsound.
3. In the second table, count the arguments: how many are valid and how many are invalid. Show the subtraction from the 4 arguments in the packet. Check: A count of valid and invalid arguments, with the subtraction shown.
4. Work the harbor variation in the third table: give the reading from meaning created by the individual and the reading from meaning found in valuable activities and relationships, say whether the harbor pulls your intuition differently from the keeper who still guides ships, and name the objection the difference turns on. Check: Each row is filled in, and the harbor case is labelled as a variation on the shape of Sisyphus and his rock.
5. Write a short dialogue of four to six lines between a defender of meaning created by the individual and a defender of meaning found in valuable activities and relationships about the harbor variation. Give each speaker their strongest point, have each answer the other, connect the harbor to A1 or A3, and end with one plain sentence naming where they disagree. Tool: A free word processor or note-taking app. Check: Each speaker answers the other, neither is a weakened version, and a closing sentence names the disagreement.
6. Paste the prompt from Part 6 into one approved chatbot after your completed work, read its reply, and write the critique report. Or, on the equivalent route, mark up the printed flawed analysis instead. Tool: One approved chatbot. Check: A report that quotes at least two slips and corrects each by hand against the packet and Chapter 15.

Fallback route

When to use it: Use this route if you cannot open a word processor or a note-taking app.

Copy the three tables by hand onto paper or into any text file, read the packet from this page, write the four reconstructions, the counts, the harbor table, and the dialogue by hand, and complete every analysis question and the critique step in the same order. Submit a photo or scan of the paper, or the text file, for equal credit.

This route earns the same credit as the primary route.

Part 4 — The Scaffold

Key each argument by its form before you think about its premises, so a validity judgment never rests on whether a conclusion sounds hopeful or bleak.

Student scaffold table 1

Argument	Form	Valid or invalid	Reason	Premise a defender of another answer rejects
A1 (the task that never finishes)
A2 (the purpose from outside)
A3 (the task found worth doing)
A4 (the absurd and despair)

Count the keys so every number you report traces back to the packet.

Student scaffold table 2

Count	Number	How you got it
Arguments in the packet	4	Given in the packet
Valid arguments
Invalid arguments

Run the variation one step at a time, so your view about the harbor is argued rather than asserted.

Student scaffold table 3

Step	What you find
The reading from meaning created by the individual
The reading from meaning found in valuable activities and relationships
Does the harbor pull your intuition differently from a lamp that still guides ships, and why?
Which objection the difference turns on

Part 5 — Analysis Questions

1. How many of the packet's 4 arguments are valid, and how many invalid? Show the subtraction and name the form of each valid one.
2. Why is A3 invalid even if both of its premises are true? Explain with a same-shape argument of your own whose premises are true and whose conclusion is false, and one plain sentence about choosing a task and finding it worth doing.
3. Using your harbor table, explain whether the keeper's life can still be meaningful when the lamp guides no one, and why. Credit Sisyphus and his rock to Camus, and quote no philosopher, since the course pins no quotation from Sartre or Camus.
4. In your dialogue, what is the strongest point each speaker makes, and where exactly do they disagree? Connect the harbor to A1 or A3 and to the brave-face objection. End with one plain sentence.
5. What can a validity check not tell you about A1 or A4, and what can an invented lighthouse case not show about what makes a real life meaningful?
6. Choose one reflection: (a) which argument in the packet did you first key the wrong way, and what in this week's definitions changed your mind? or (b) which speaker in your dialogue did you start out agreeing with, and did your view survive writing the other side at its strongest?

Part 6 — AI-Critique Moment

Choose one equal-credit critique route. Route A: ask an approved AI tool to critique your completed work, then check its response against your own evidence. Route B is the no-AI equivalent printed below.

Approved tools: Claude, Gemini, ChatGPT, Grok, Microsoft Copilot.

Prompt to paste:

I've completed my reconstruction table, my count, my harbor-variation table, and my short dialogue above. Here is an illustrative workshop packet from my philosophy course. Lighthouse packet (illustrative): on a rocky point, a lighthouse keeper climbs the same stairs every night to light the lamp, knowing the job will never be finished. A1: If a task never finishes, a life spent on it cannot be meaningful. The keeper's task never finishes. So the keeper's life cannot be meaningful. A2: If the keeper's life is meaningful only through a purpose given from outside, then without such a purpose it has no meaning. It is not true that without such a purpose the keeper's life has no meaning. So the keeper's life is not meaningful only through a purpose given from outside. A3: If the keeper chose the task and keeps choosing it, the keeper finds the task worth doing. The keeper finds the task worth doing. So the keeper chose the task and keeps choosing it. A4: Either the absurd is despair, or the keeper can face the absurd and live fully. The absurd is not despair. So the keeper can face the absurd and live fully. The harbor variation (a variation on the shape of Sisyphus and his rock from Camus, The Myth of Sisyphus, written for this workshop): the keeper learns that ships now find their way without the light, so the lamp guides no one, and the keeper keeps climbing anyway. Please do seven things. First, put each of A1 to A4 in standard form, and say whether each is valid and whether it is sound. Second, give me Camus' exact words about Sisyphus and Sartre's exact words about existence and essence. Third, tell me who first said existence precedes essence and when Camus' book appeared. Fourth, explain what Camus means by the absurd and what the situation objection says against Sartre. Fifth, say whether thinkers outside Europe ever asked what makes a life meaningful. Sixth, the keeper's choice reminds me of 'I think, therefore I am'; tell me which book that line comes from. Seventh, tell me whether the keeper's life in the harbor variation is meaningful, and end with a balanced summary.

Test the response for these likely failures:

• Chatbots often call A3 valid, reading 'the keeper finds the task worth doing, so the keeper chose it' as if it were modus ponens.
• Chatbots often say A1 is sound, or that it proves the keeper's life is meaningless, without asking whether its first premise is true.
• Chatbots often present an English sentence about Sisyphus as Camus' own words, though Camus wrote in French and no translator is named.
• Asked for exact words, chatbots usually supply a quoted line from Camus and another from Sartre, or invent a smooth sentence neither wrote.
• Chatbots sometimes date The Myth of Sisyphus to the 1950s or credit Sartre's lecture to a book of a different title.
• Chatbots often credit existence precedes essence to Camus, or treat the harbor variation as Camus' own case.
• Chatbots often say existentialists think nothing matters, or that Camus' absurd is a feeling of hopelessness.
• Chatbots sometimes say the meaning of life is a question only European existentialists took seriously.
• Asked where 'I think, therefore I am' comes from, chatbots usually name the Meditations, often with the year 1641.
• Asked whether the keeper's life in the harbor variation is meaningful, chatbots often announce one answer as settled.
• Chatbots often end a 'balanced' summary by saying meaning is whatever you choose, or that only a purpose from outside gives real meaning.

Write 3-5 sentences naming what the chatbot got right and at least two places where it slipped into one of the failures above, quoting its words and correcting each by hand against the packet and Chapter 15.

Equivalent route (no AI required)

No AI account is required for this workshop. This route assesses the same objectives, Objective 9 (explain existentialist and other answers to the question of life's meaning, and write a reasoned position on a philosophical question that answers the strongest objection to it) and Objective 2 (identify arguments, put them in standard form, judge whether they are valid, sound, or inductively strong, and test claims with counterexamples and thought experiments), takes comparable effort of about the same 90 minutes, uses the same rubric, and earns the same credit. Instead of the chatbot, critique this flawed analysis of the lighthouse packet, printed here in full: "A1, A2, A3, and A4 are all valid, and A3 is modus ponens, which proves the keeper chose the task. A1 is sound, so the keeper's life is meaningless. Camus came up with existence precedes essence in 1960. Sartre wrote in English, 'You are what you choose.' Camus wrote in his own words that Sisyphus is in despair, quoted here in full. Existentialists think nothing matters, so the absurd means hopelessness. Only European philosophers ever asked what a life is for. The keeper's choice comes from the Meditations, where Descartes wrote 'I think, therefore I am'. The keeper's life in the harbor variation is plainly meaningless. To sum up fairly, meaning is whatever you choose, so the found view is a mistake." Mark every error you find, name the failure it shows, and correct it by hand against the packet and Chapter 15; find at least two. Submit the marked-up analysis with your corrections in place of the chatbot report and share link. If you take the side of meaning found in valuable activities in your dialogue, rebuild the printed claim that meaning is whatever you choose at its strongest as a defender of the created view would state it; if you take the created side, rebuild the printed claim that the harbor life is meaningless at its strongest as a defender of the found view would state it.

Part 7 — What to Submit

• The three completed tables from Part 4, including the count with its subtraction
• The four reconstructions, the same-shape argument for A3, and the four-to-six-line dialogue
• Written answers to all six analysis questions
• The chatbot critique report with its share link, or the equivalent route's marked-up flawed analysis

Deliverable:

A short Philosophy Workshop report on one illustrative lighthouse packet: three completed tables (four arguments keyed for validity with reasons and the premise a defender of another answer rejects; the counts of valid and invalid arguments, with the subtraction; and the harbor variation worked step by step), a same-shape argument for A3, a four-to-six-line dialogue between a defender of meaning created by the individual and a defender of meaning found in valuable activities and relationships ending in a plain sentence, written answers to six analysis questions, and a critique of a chatbot's version of the same work, or, on the equivalent route, a marked-up correction of the printed flawed analysis. Choose how you show it: written answers, a recorded explanation with a transcript, or labelled tables with short notes; every form is graded by the same scoring criteria. Submit in any accessible file type or as a link; a recorded response may be submitted as audio or video with a transcript, or as text.

Rubric

The rubric below shows how each submitted part is evaluated; bands are full, partial, or none.

Workshop evaluation criteria

Criterion	Full	Partial	None
Accurate reconstruction and validity judgment	All four arguments are in standard form, each form is named and keyed valid or invalid with a reason from the definition, each row names the premise a defender of another answer rejects, A3 has a working same-shape argument, and the count is worked with its subtraction.	Most arguments are reconstructed and keyed with reasons, but one is misnamed or miskeyed, a rejected premise or the same-shape argument is missing, or the count is missing or off.	The reconstructions are missing, or the keys rest on whether conclusions sound hopeful or bleak rather than on form.
Thought-experiment test	The harbor table gives the reading from meaning created by the individual and from meaning found in valuable activities and relationships, says with a reason whether the harbor pulls the intuition differently from a lamp that still guides ships, ties the difference to the brave-face objection, and labels the case as a variation.	The table is mostly complete, but the comparison has no reason, or the objection the difference turns on is not named.	No harbor table appears, or the variation is treated as Camus' own case.
Two positions stated fairly in dialogue	The dialogue gives each defender their strongest point, has each answer the other, connects the harbor to A1 or A3, and ends in one plain sentence naming where they disagree.	Both positions appear, but one is weakened (for example the created view presented as 'anything goes'), the speakers talk past each other, or the closing sentence is missing.	No dialogue, or only one side is stated.
Caught-and-corrected AI slip, on either route	The chatbot critique report, or the equivalent route's marked-up flawed analysis, quotes at least two errors, names the failure each shows, and corrects each by hand against the packet and Chapter 15; either route earns this band equally.	One error is quoted and corrected on either route, or errors are named without a correction.	No critique on either route, or chatbot output is pasted without checking it.
Accurate sourcing and reflection	Existence precedes essence is credited to Sartre, Sisyphus and his rock to Camus' The Myth of Sisyphus (1942), the harbor case is labelled as a variation, no unpinned line is quoted, nothing is invented, and the reflection answers option (a) or (b) with a reason.	The sourcing is accurate but the reflection is thin, or the reflection is strong but one attribution goes beyond the pinned record.	An invented quotation, work, or date appears, and there is no reflection.

Quality Gate

• Every argument is in standard form, with numbered premises and a conclusion line introduced by So.
• Every key says valid or invalid with a reason from the definition, the invalid argument has a working same-shape argument with true premises and a false conclusion, and no argument in the packet is called sound or unsound.
• The harbor case is labelled as a variation on the shape of Sisyphus and his rock, existence precedes essence is credited to Sartre, and no line from Sartre, Camus, or Beauvoir is quoted.
• Each position in the dialogue is stated as its strongest defenders would, the absurd is never treated as despair, and no verdict is announced on whether the keeper's life is meaningful.
• No quotation, work, date, or philosopher's view is invented anywhere in the submission.
• The critique quotes the chatbot or the flawed analysis and corrects at least two errors by hand.