Read
Build the mental model
Move through the guided explanation first so the central distinction and purpose are clear before you evaluate your own work.
Foundations
From Natural Language to Structure
Students learn to extract arguments from natural language, identify implicit premises, and produce a semi-formal structured outline as a bridge to full symbolic formalization.
Read for structure, not just vocabulary. The goal is to learn how natural-language claims are converted into a cleaner formal shape.
Start Here
What this lesson is helping you do
Students learn to extract arguments from natural language, identify implicit premises, and produce a semi-formal structured outline as a bridge to full symbolic formalization. The practice in this lesson depends on understanding Premise, Conclusion, Indicator Words, and Formalization and applying tools such as Relevance Standard and Sufficiency Standard correctly.
How to approach it
Read for structure, not just vocabulary. The goal is to learn how natural-language claims are converted into a cleaner formal shape.
What the practice is building
You will put the explanation to work through formalization practice, analysis practice, diagnosis practice, comparison exercise, rapid identification, evaluation practice, and argument building activities, so the goal is not just to recognize the idea but to use it under your own control.
What success should let you do
Extract arguments from 4 natural-language passages, identify all implicit premises, and produce a correct standard-form and semi-symbolic outline for each.
Reading Path
Move through the lesson in this order
The page is designed to teach before it tests. Use this sequence to keep the reading, examples, and practice in the right relationship.
Study
Watch the move in context
Use the worked examples to see how the reasoning behaves when someone else performs it carefully.
Do
Practice with a standard
Only then move into the activities, using the pause-and-check prompts as a final checkpoint before you submit.
Guided Explanation
Read this before you try the activity
These sections give the learner a usable mental model first, so the practice feels like application rather than guesswork.
Orientation
Read for the central move
Students learn to extract arguments from natural language, identify implicit premises, and produce a semi-formal structured outline as a bridge to full symbolic formalization.
Keep your attention on Premise, Conclusion, Indicator Words, and Formalization while you read. Those ideas are the lens that will make the examples and practice intelligible.
Read for structure before you reach for symbols. Identify the atomic claims, the main connective, and the conclusion you are trying to preserve when you translate.
What to look for
- Be able to explain Premise in your own words.
- Notice how Conclusion differs from the first concept instead of blending them together.
- Keep the mastery target in mind: Extract arguments from 4 natural-language passages, identify all implicit premises, and produce a correct standard-form and semi-symbolic outline for each.
If the main concepts stay clear in your head, the practice will feel like applying a model instead of guessing.
What to notice
Use the examples as a reading model
Before you practice, work through Extracting an Argument with Indicator Words and Recovering an Implicit Premise and ask what each example is trying to make visible.
Judge each move against standards such as Relevance Standard, Sufficiency Standard, and Deductive Validity Standard. The point is to see what would make the reasoning count as acceptable or defective.
If you need to translate messy language into cleaner structure, lean on patterns such as Argument Extraction from Natural Language and Semi-Symbolic Argument Outline before you start writing your own answer.
What to look for
- Notice where the example marks off the premises from the conclusion.
- Use Relevance Standard as an actual test, not just a vocabulary term.
- Track the main connective or structural pattern before you rewrite anything.
- Watch for this common miss: Do not add implicit premises that go beyond what the argument requires; only add what is needed to connect the explicit premises to the conclusion.
A worked example matters only if you can say what move it is modeling and where students usually slip.
Before you practice
Set up the practice before you answer
You will apply the lesson through 15 activitys, including Extract and Structure and Build a Semi-Symbolic Outline. Read the prompt, but do not type immediately; first decide what a strong answer would have to show.
The practice format here is formalization practice, analysis practice, diagnosis practice, comparison exercise, rapid identification, evaluation practice, and argument building, so prepare for a task that asks you to show control, not just recognition.
Before submitting, make sure the symbolic version preserves the same logical structure as the ordinary-language argument instead of just copying surface grammar.
What to look for
- Have I identified all indicator words in the passage?
- Does my standard-form argument capture everything the original passage was trying to argue?
- Is every implicit premise I added genuinely required for the argument to work?
- Avoid: Do not add implicit premises that go beyond what the argument requires; only add what is needed to connect the explicit premises to the conclusion.
Pause long enough to know what standard you are about to use before you start drafting.
Historical context
Why this tool exists
The historical notes connect this lesson to figures such as Chrysippus and the Stoics so the method feels motivated rather than arbitrary.
If the history feels remote, use it to answer one practical question: what confusion, error, or limitation was this technique designed to overcome?
History is useful when it sharpens the purpose of the method you are about to use.
Core Ideas
The main concepts to keep in view
Use these as anchors while you read the example and draft your response. If the concepts blur together, the practice usually blurs too.
Premise
A statement offered as evidence or a reason in support of an argument's conclusion.
Why it matters: Identifying premises is the first step in analyzing any argument.
Conclusion
The statement that an argument claims to establish on the basis of its premises.
Why it matters: The conclusion is what the arguer wants the audience to accept.
Indicator Words
Words or phrases such as 'therefore,' 'because,' and 'since' that signal the presence of an argument and mark premises or conclusions.
Why it matters: Indicator words are essential tools for finding arguments embedded in ordinary language.
Formalization
The process of translating natural-language arguments into a structured symbolic or semi-symbolic form.
Why it matters: Formalization makes logical structure explicit and enables rigorous analysis.
Reference
Open these only when you need the extra structure
How the lesson is meant to unfold
Concept Intro
The core idea is defined and separated from nearby confusions.
Formalization Demo
The lesson shows how the same reasoning looks once its structure is made explicit.
Worked Example
A complete example demonstrates what correct reasoning looks like in context.
Guided Practice
You apply the idea with scaffolding still visible.
Independent Practice
You work more freely, with less support, to prove the idea is sticking.
Assessment Advice
Use these prompts to judge whether your reasoning meets the standard.
Mastery Check
The final target tells you what successful understanding should enable you to do.
Reasoning tools and formal patterns
Rules and standards
These are the criteria the unit uses to judge whether your reasoning is actually sound.
Relevance Standard
Each premise of an argument must bear directly on the truth or probability of the conclusion.
Common failures
- A premise addresses a different topic than the conclusion.
- A premise appeals to emotion or authority rather than providing evidence for the conclusion.
Sufficiency Standard
The premises, taken together, must provide enough support to justify accepting the conclusion.
Common failures
- The argument draws a sweeping conclusion from a single example.
- Key evidence needed to support the conclusion is missing entirely.
Deductive Validity Standard
In a valid deductive argument, if the premises are true, the conclusion must be true.
Common failures
- The student judges validity by whether the conclusion sounds plausible rather than by logical structure.
- The student conflates truth of premises with validity of the argument form.
Argument Identification Standard
A passage contains an argument only if it presents one or more claims intended as reasons for accepting another claim.
Common failures
- The student treats a mere description or explanation as an argument.
- The student fails to identify an implicit premise that is essential to the argument.
Patterns
Use these when you need to turn a messy passage into a cleaner logical structure before evaluating it.
Argument Extraction from Natural Language
Input form
natural_language_passage
Output form
structured_argument
Steps
- Read the passage and identify indicator words.
- Determine which statement is the conclusion.
- List the explicit premises.
- Check for implicit premises and make them explicit.
- Write the argument in standard form: premises listed above a line, conclusion below.
Watch for
- Confusing background information with premises.
- Missing an implicit premise that the argument relies on.
- Misidentifying the conclusion because the passage places it first.
Semi-Symbolic Argument Outline
Input form
structured_argument
Output form
semi_symbolic_form
Steps
- Assign labels (P1, P2, etc.) to each premise and C to the conclusion.
- Identify the logical relationship between premises (conjunction, conditional, disjunction).
- Represent the relationship using arrow or ampersand notation.
- Verify that the semi-symbolic outline preserves the original argument's meaning.
Watch for
- Assigning the same label to different claims.
- Using a conditional arrow when the relationship is actually conjunctive.
- Losing important qualifiers when abbreviating premises.
Worked Through
Examples that model the standard before you try it
Do not skim these. A worked example earns its place when you can point to the exact move it is modeling and the mistake it is trying to prevent.
Worked Example
Extracting an Argument with Indicator Words
Indicator words like 'since,' 'because,' and 'therefore' signal the roles of statements in an argument. Recognizing them is the first step in extracting structure from prose.
Content
- Original passage: 'Since all registered voters received a ballot, and Maria is a registered voter, it follows that Maria received a ballot.'
- Indicator words: 'Since' (premise indicator), 'it follows that' (conclusion indicator).
- P1: All registered voters received a ballot.
- P2: Maria is a registered voter.
- C: Maria received a ballot.
Worked Example
Recovering an Implicit Premise
Many real-world arguments leave a premise unstated because the speaker considers it obvious. Making implicit premises explicit is essential for fair evaluation.
Content
- Original passage: 'Carlos must be at least 18, because he voted in the election.'
- Explicit premise: Carlos voted in the election.
- Implicit premise: Only people who are at least 18 can vote in the election.
- Conclusion: Carlos is at least 18.
- Semi-symbolic: P1: Carlos voted. P2 (implicit): Voting requires being at least 18. Therefore, C: Carlos is at least 18.
Pause and Check
Questions to use before you move into practice
Self-check questions
- Have I identified all indicator words in the passage?
- Does my standard-form argument capture everything the original passage was trying to argue?
- Is every implicit premise I added genuinely required for the argument to work?
Practice
Now apply the idea yourself
Move into practice only after you can name the standard you are using and the structure you are trying to preserve or evaluate.
Formalization Practice
FoundationsExtract and Structure
Read each paragraph and extract the argument it contains. List the premises (including any implicit ones), state the conclusion, and write the argument in standard form.
Paragraphs to extract
Choose one paragraph below. Identify indicator words, recover any needed implicit premise, and rewrite the reasoning in clear standard form.
Passage A
Because the campus shuttle stops at every residence hall, Elena can get to the library without a car. So she does not need to pay for downtown parking this week.
Look for the explicit support claim and any hidden assumption about how Elena reaches the library.
Passage B
Only certified lab assistants can access the chemical storage room. Malik accessed the chemical storage room yesterday. Therefore, Malik must be a certified lab assistant.
Notice the conditional structure hiding inside the ordinary-language wording.
Passage C
Since the trail was closed after the storm, the hikers had to take the longer route, which explains why they arrived after sunset.
Decide which claims are functioning as premises, which claim is the conclusion, and whether any bridge premise needs to be made explicit.
Use one of the short arguments above. Pull out the premises and conclusion, then rewrite the argument in a cleaner, more analysable form.
Formalization Practice
FoundationsBuild a Semi-Symbolic Outline
Take each standard-form argument you produced and create a semi-symbolic outline using labels (P1, P2, C) and notation for the logical relationship between premises.
Arguments to outline
Use one of the extracted arguments below. Label the premises and conclusion, then show the inferential relationship in a clean semi-symbolic outline.
Passage A
If a student completes all rehearsal checks, the performance system unlocks. Jordan completed all rehearsal checks. Therefore, the performance system unlocks for Jordan.
Show clearly how the premises combine to support the conclusion and where the conditional relation belongs.
Passage B
All registered tutors have campus IDs. Priya is a registered tutor. Therefore, Priya has a campus ID.
Use a simple P1, P2, C format to make the support relation explicit.
Passage C
The lecture must be online or postponed. It is not postponed. So the lecture must be online.
Make the disjunctive structure visible in your labeled outline.
Use one of the short arguments above. Pull out the premises and conclusion, then rewrite the argument in a cleaner, more analysable form.
Analysis Practice
FoundationsApply the Concepts: From Natural Language to Structure
Analyze each passage below using the concepts from this lesson. Identify key logical features and explain your reasoning.
Practice scenarios
Work through each scenario carefully. Apply the concepts from this lesson.
Scenario 1
A local council argues: every park that has been surveyed shows declining bird populations. The marsh reserve has not been surveyed. Therefore, we cannot conclude anything about its bird population.
Scenario 2
The professor told the class: 'Either your hypothesis is testable, or it does not belong in a scientific paper.' Maria's hypothesis predicts no observable outcomes.
Scenario 3
A fitness study concludes that runners who stretch before exercise report fewer injuries. However, runners who stretch may also be more cautious in other ways.
Pick one of the passages above and map how the reasons are supposed to support the conclusion.
Diagnosis Practice
FoundationsSpot the Error: From Natural Language to Structure
Each passage contains a logical mistake. Identify the error, name it if possible, and explain why the reasoning fails.
Practice scenarios
Work through each scenario carefully. Apply the concepts from this lesson.
Case A
Everyone at the meeting agreed the policy is fair. Since the meeting was open to the public, we can say the public agrees the policy is fair.
Case B
No reptile is a mammal. No mammal is an insect. Therefore, no reptile is an insect.
Case C
The forecast said 70% chance of rain. It did not rain. Therefore, the forecast was wrong.
Use one of the passages above. Name the weakness, explain the violated standard, and show how the reasoning should be repaired.
Comparison Exercise
FoundationsCompare and Connect: From Natural Language to Structure
Compare the reasoning in the passages below. Identify similarities, differences, and which argument is stronger, explaining your criteria.
Practice scenarios
Work through each scenario carefully. Apply the concepts from this lesson.
Argument X
Since all observed swans in Europe were white, all swans are white.
Argument Y
Since the chemical formula for water is H2O in every sample we have tested, water is H2O.
Argument Z
Since every student I asked preferred online classes, all students prefer online classes.
Choose one of the passages above and decide whether it is an argument. Then explain how you know.
Analysis Practice
FoundationsDeep Practice: From Natural Language to Structure
Apply the concepts from this lesson to more complex scenarios. Work through each carefully and explain your reasoning in full.
Advanced practice scenarios
Each scenario tests your ability to apply foundational logic concepts in realistic contexts.
Case 1
An editorial argues: 'Standardized testing must be eliminated because it causes student anxiety. And since anything that causes anxiety is harmful, standardized testing is harmful.' Analyze the argument's structure, identify any hidden premises, and evaluate its strength.
Case 2
A scientist writes: 'We observed that 90% of treated mice recovered, while only 30% of untreated mice recovered. The treatment appears effective. However, the treated group was also younger on average.' Identify the argument, the potential confounder, and what additional information would strengthen or weaken the conclusion.
Case 3
A philosopher claims: 'Either free will is an illusion, or moral responsibility is justified. Neuroscience has shown that brain activity precedes conscious decisions. Therefore, free will is probably an illusion, and moral responsibility may not be justified.' Map the logical structure and evaluate whether the conclusion follows.
Pick one of the passages above and map how the reasons are supposed to support the conclusion.
Analysis Practice
FoundationsReal-World Transfer: From Natural Language to Structure
Apply what you have learned to these real-world contexts. Analyze each scenario using the tools and concepts from this lesson.
Transfer practice
Connect the concepts from this lesson to contexts outside the classroom.
Media literacy
A social media post claims: 'A new study proves that video games improve intelligence.' The post links to a study of 40 college students who played puzzle games for 2 weeks and showed improved scores on one type of spatial reasoning test. Evaluate this claim using what you know about arguments, evidence, and reasoning.
Everyday reasoning
A friend argues: 'I should not get vaccinated because my cousin got vaccinated and still got sick. Also, I read an article that said natural immunity is better.' Identify the types of reasoning, assess their strength, and explain what additional evidence would be relevant.
Professional context
A manager says: 'Our last three hires from University X performed well, so we should recruit exclusively from University X.' Analyze the reasoning type, identify potential problems, and suggest a better approach.
Pick one of the passages above and map how the reasons are supposed to support the conclusion.
Rapid Identification
FoundationsTimed Drill: From Natural Language to Structure
Work through these quickly. For each passage, identify whether it contains an argument, name its type if so, and point to the conclusion. Aim for speed and accuracy.
Quick-fire argument identification
For each item, decide: argument or not? If yes, what type and what is the conclusion? Under 45 seconds per item.
Item 1
The bridge was built in 1962. It was designed by a local engineering firm and cost $2.3 million.
Item 2
Because the experiment was not replicated, the results should be treated with caution.
Item 3
Sharks have survived five mass extinction events, so they are remarkably resilient species.
Item 4
If the evidence was obtained illegally, the court must exclude it. The evidence was obtained without a warrant. Warrantless searches are illegal. Therefore, the court must exclude the evidence.
Item 5
The town council meets every second Tuesday. This week is the second Tuesday. The library will be used for the meeting.
Item 6
The most likely reason the power went out is the thunderstorm, since the outage started exactly when lightning struck the transformer.
Choose one of the passages above and decide whether it is an argument. Then explain how you know.
Evaluation Practice
FoundationsPeer Review: From Natural Language to Structure
Below are sample student attempts to identify and analyze arguments. Evaluate each response: Is the identification correct? Is the analysis accurate? What feedback would you give?
Evaluate student argument analyses
Each student tried to break down an argument into premises and conclusion. Assess their work.
Student A's work
Passage: 'Since exercise reduces stress and stress causes health problems, exercise prevents health problems.' Student A wrote: 'Premise 1: Exercise reduces stress. Premise 2: Stress causes health problems. Conclusion: Exercise prevents health problems. This is a valid deductive argument.'
Student B's work
Passage: 'The committee should approve the budget because it was prepared by experts.' Student B wrote: 'This is not an argument. It is just a recommendation.'
Student C's work
Passage: 'Most doctors recommend regular check-ups. Regular check-ups catch diseases early. Early detection saves lives. Therefore, you should get regular check-ups.' Student C wrote: 'Premise 1: Most doctors recommend check-ups. Conclusion: You should get check-ups. This is an inductive argument from authority.'
Student D's work
Passage: 'It will probably rain tomorrow because the barometric pressure is dropping and clouds are moving in from the west.' Student D wrote: 'Premise 1: Barometric pressure is dropping. Premise 2: Clouds are moving in. Conclusion: It will probably rain. This is an inductive argument based on observed indicators. Strength: moderate, since weather patterns are not perfectly predictable.'
Choose one of the passages above and evaluate it using the right standard for its reasoning mode.
Argument Building
FoundationsConstruction Challenge: From Natural Language to Structure
Build arguments from scratch. For each task, construct a well-structured argument with clear premises and a conclusion. Identify the reasoning type you are using.
Construct original arguments
For each prompt, build a complete argument from scratch. Clearly state premises, conclusion, and reasoning type.
Task 1
Construct a deductive argument with two premises that concludes: 'This substance is not an acid.' Make sure the argument is valid.
Task 2
Build an inductive argument with at least three pieces of evidence supporting the conclusion: 'Regular reading improves vocabulary.' Make it as strong as you can.
Task 3
Construct an argument that uses an indicator word for the conclusion and a different indicator word for at least one premise. The topic should be about environmental policy.
Task 4
Build two different arguments for the same conclusion: 'Public libraries should remain publicly funded.' One argument should be deductive, the other inductive. Explain why one might be more persuasive than the other.
Use one of the sentences above and move carefully from ordinary language to a clearer predicate-logic style representation.
Diagnosis Practice
FoundationsCounterexample Challenge: From Natural Language to Structure
For each argument, construct a counterexample or identify a scenario that shows the reasoning is flawed. Explain what the counterexample reveals about the argument's weakness.
Counterexamples and edge cases
Each argument has a flaw. Expose it with a specific counterexample.
Argument 1
Every time I have washed my car, it rained the next day. Therefore, washing my car causes rain.
Argument 2
No one at the party complained about the food. Therefore, everyone enjoyed the food.
Argument 3
This policy worked well in Sweden. Therefore, it will work well in Brazil.
Argument 4
The candidate won 60% of the vote in the primary. Therefore, they will win the general election.
Argument 5
All the reviews on the website are positive. Therefore, the product is excellent.
Use one of the passages above. Name the weakness, explain the violated standard, and show how the reasoning should be repaired.
Analysis Practice
FoundationsIntegration Exercise: From Natural Language to Structure
These exercises connect the concepts from this lesson to ideas across different reasoning domains. Apply foundational concepts to scenarios that require multiple analytical tools.
Cross-cutting foundational exercises
Each scenario tests your ability to apply foundational logic concepts alongside other analytical skills.
Scenario 1
A news article reports: 'Scientists have proven that coffee is good for you, according to a new study of 500 adults who drink coffee daily.' Identify all arguments in this claim, classify the reasoning type(s), evaluate the evidence quality, and explain what additional information would be needed.
Scenario 2
A school board argues: 'Since standardized test scores are the best measure of student learning, and our test scores have risen 10% this year, our educational quality has improved.' Identify the premises and conclusion, classify the reasoning, spot any hidden assumptions, and construct an alternative explanation for the score increase.
Scenario 3
A city planner argues: 'If we build more bike lanes, more people will bike. More biking reduces car traffic. Less car traffic means less pollution. Therefore, building bike lanes will reduce pollution.' Map the argument structure, evaluate each inferential step separately (some may be deductive, others inductive), and identify the weakest link.
Scenario 4
An investor reasons: 'This company's stock has risen every year for the past eight years. The CEO is talented and the industry is growing. I should invest heavily.' Identify all reasoning types present, evaluate each one, and explain how the different types of reasoning interact in this argument.
Pick one of the passages above and map how the reasons are supposed to support the conclusion.
Diagnosis Practice
FoundationsMisconception Clinic: From Natural Language to Structure
Each item presents a common misconception about arguments, reasoning, or logic. Identify the misconception, explain why it is wrong, and state the correct principle.
Common logic misconceptions
Diagnose and correct each misconception about basic logic and arguments.
Misconception 1
A student says: 'An argument with true premises must have a true conclusion.'
Misconception 2
A student claims: 'If two people disagree, at least one of them must be using bad logic.'
Misconception 3
A student writes: 'Opinions cannot be arguments because arguments require facts, not opinions.'
Misconception 4
A student argues: 'A strong argument is one that is persuasive. If people are convinced by it, it must be a good argument.'
Misconception 5
A student says: 'An explanation and an argument are the same thing -- both provide reasons for something.'
Use one of the passages above. Name the weakness, explain the violated standard, and show how the reasoning should be repaired.
Analysis Practice
FoundationsScaffolded Analysis: From Natural Language to Structure
Build an argument analysis in stages. Each task provides a passage and walks you through the analysis process step by step. Complete each stage before moving on.
Step-by-step argument analysis
Analyze each argument progressively, one skill at a time.
Scaffold 1
Passage: 'Because violent crime has increased 15% this year and the police budget was cut 10% last year, the budget cuts are responsible for the crime increase. Therefore, the city council should restore police funding.' Stage 1: Identify all premises and the conclusion. Stage 2: Classify the reasoning type. Stage 3: Identify any hidden premises or assumptions. Stage 4: Evaluate the strength of the inference. Stage 5: Suggest what additional evidence would strengthen or weaken this argument.
Scaffold 2
Passage: 'Three out of four dentists recommend this toothpaste. Since expert opinion is reliable, you should use this toothpaste. After all, if experts recommend something, it must be good.' Stage 1: Put the argument in standard form. Stage 2: Identify the reasoning type for each inferential step. Stage 3: Spot any logical errors or questionable assumptions. Stage 4: Rewrite the argument to make it stronger.
Scaffold 3
Passage: 'Countries that invest in education have stronger economies. Our country should invest more in education to strengthen the economy. This is proven by the examples of South Korea, Finland, and Singapore.' Stage 1: Map the argument structure. Stage 2: Identify whether this is primarily deductive, inductive, or abductive. Stage 3: Evaluate the evidence. Stage 4: Identify the strongest objection to this argument. Stage 5: Revise the argument to address that objection.
Pick one of the passages above and map how the reasons are supposed to support the conclusion.
Analysis Practice
FoundationsSynthesis Review: From Natural Language to Structure
These exercises combine everything you have learned about arguments, reasoning types, and evaluation. Each scenario requires you to identify, classify, analyze, evaluate, and improve an argument.
Comprehensive foundations review
Apply all foundational logic skills together.
Comprehensive 1
A school district superintendent argues: 'Our district should adopt year-round schooling. Studies show students in year-round schools retain 10% more knowledge. Teachers in year-round districts report higher job satisfaction. The only objection is tradition, but tradition is not a good reason to hold back progress. Other districts that switched have seen rising test scores within two years.' Perform a complete analysis: identify all premises and the conclusion, classify each reasoning step, find any hidden assumptions, spot any logical errors, evaluate the overall strength, and rewrite the argument to make it stronger.
Comprehensive 2
A debate transcript: Speaker A says 'Social media causes depression -- the data is clear.' Speaker B responds 'That is correlation, not causation. Besides, my teenagers use social media constantly and they are perfectly happy.' Speaker A replies 'Your children are exceptions. The overall trend is undeniable.' Analyze each speaker's reasoning: identify argument types, evaluate their strength, identify logical errors, find hidden assumptions, and draft what a well-reasoned third speaker should say.
Pick one of the passages above and map how the reasons are supposed to support the conclusion.
Argument Mapper
Build an argument diagram by adding premises, sub-conclusions, and a conclusion. Link nodes to show which claims support which.
Add nodes above, or load a template to get started. Each node represents a proposition in your argument.
■ Premise■ Sub-conclusion■ Conclusion
Animated Explainers
Step-by-step visual walkthroughs of key concepts. Click to start.
Read the explanation carefully before jumping to activities!
Further Support
Open these only if you need extra help or context
Mistakes to avoid before submitting
- Do not add implicit premises that go beyond what the argument requires; only add what is needed to connect the explicit premises to the conclusion.
- Do not strip away important qualifiers when converting prose to standard form.
Where students usually go wrong
Failing to notice indicator words embedded in complex sentences.
Adding an implicit premise that is not actually required by the argument.
Distorting the argument's meaning during the transition from prose to standard form.
Historical context for this way of reasoning
Chrysippus and the Stoics
The Stoics were among the first to analyze argument forms at the propositional level, paving the way for the formalization techniques taught in modern logic.