Presentation 2a: Identifying Statements and Arguments

Summary

This lecture introduces the concept of arguments and statements in reasoning. It explains that an argument is a set of statements where the premises support the conclusion. The lecture teaches how to distinguish statements from other expressions using the 'It is true that' test and identifies premise and conclusion indicators, such as 'because' and 'therefore', which signal parts of an argument. It also provides an exercise to practice identifying these components in a given argument.

Takeaways

• 💬 Arguments consist of statements, one of which is the conclusion, supported by the premises.
• 🔍 The difference between statements and other expressions (interrogatives and imperatives) is that only statements assert that something is the case.
• 📝 Statements are also called declarative sentences, and they are the building blocks of arguments.
• 📜 An argument’s purpose is to provide reasons for accepting a conclusion, rather than just stating it.
• 🧠 Premises and conclusions can be identified using specific words and phrases known as 'premise and conclusion indicators.'
• 🛠 Words like 'because,' 'since,' and 'for' are common premise indicators, while 'therefore,' 'so,' and 'hence' often signal conclusions.
• ⚠️ Some indicator words, like 'since,' can be used in non-argumentative contexts, making it important to interpret their function in context.
• ✅ A simple test for identifying statements is to append 'It is true that' to see if the result is grammatical.
• 📊 Premise and conclusion indicators help recognize when an argument is being presented and which statements play which roles.
• 🎓 Example exercise: In 'People who study hard will pass. Isabelle studies hard, so she will pass,' the conclusion is 'Isabelle will pass,' indicated by the word 'so.'

Q & A

What is the main focus of lecture 2a?

The main focus of lecture 2a is on identifying statements and arguments, explaining what they are, and how to analyze them.

What is an argument according to the lecture?

An argument is a set of statements where one statement (the conclusion) is supposed to be supported by the others (the premises).

How does the lecture illustrate the concept of an argument?

The lecture uses the example of three statements: 'It’s raining', 'If it’s raining, then it is wet outside', and 'So, it is wet outside', where the first two statements are meant to support the last one.

What is the purpose of arguments as explained in the lecture?

The purpose of arguments is to provide reasons for accepting a conclusion, not just telling someone what to believe but also why they should believe it.

What is a statement as defined in the lecture?

A statement is a sentence or part of a sentence that asserts something is the case, also known as a declarative sentence.

How can you test if an expression is a statement according to the lecture?

You can test if an expression is a statement by appending 'It is true that' to the beginning of it and checking if the result is grammatical.

What are the three types of sentences or parts of sentences mentioned in the lecture?

The three types of sentences or parts of sentences mentioned are declarative sentences (statements), interrogative sentences (questions), and imperative sentences (commands).

What is the role of statements in arguments?

Statements play the roles of premises and conclusions in arguments, as they are what an argument aims to convince someone of and what it takes for granted.

What are premise and conclusion indicators?

Premise and conclusion indicators are words and phrases that suggest whether a statement is a premise or conclusion in an argument.

Can you provide an example of a premise indicator from the lecture?

An example of a premise indicator is 'because', 'since', 'for', 'after all', etc.

Can you provide an example of a conclusion indicator from the lecture?

An example of a conclusion indicator is 'therefore', 'so', 'thus', 'hence', etc.

How does the lecture suggest identifying arguments in practice?

The lecture suggests identifying arguments by looking for premise and conclusion indicators and understanding whether some statements are intended to support others.

Outlines

00:00

💡 Introduction to Arguments and Statements

In this opening, the lecture introduces the concept of arguments as bits of reasoning and explains the difference between statements and other expressions. The speaker outlines the goal of the lecture: to distinguish between statements and non-statements and to identify premises and conclusions in arguments. An example of a simple argument about rain is provided to illustrate how statements form an argument by supporting a conclusion.

05:00

🧠 Importance of Critical Thinking

The lecture highlights how arguments help us think critically, referencing an example from a previous week about choosing a major. Arguments provide reasons for accepting a conclusion, and the ability to evaluate arguments helps us determine if there is sufficient reason to believe a conclusion. This segment emphasizes the relevance of learning how to understand and assess arguments in everyday reasoning.

🔎 Defining Statements

Statements, also known as declarative sentences, are defined as expressions that assert something is the case. The lecture contrasts statements with interrogative (questions) and imperative (commands) sentences, explaining that only statements can make up arguments. A test for identifying statements is introduced: appending 'It is true that' to the beginning of a sentence to see if it remains grammatical. Examples of true, false, and non-statements are given.

🧩 Identifying Arguments

The lecture returns to arguments, explaining that identifying them 'in the wild' requires recognizing when statements are intended to support one another. Certain words, called premise and conclusion indicators, can signal the presence of arguments. Examples of indicators like 'therefore' for conclusions and 'after all' for premises are provided to help the listener identify arguments more easily.

📜 Premise Indicators

Premise indicators are expressions that signal a premise is being presented. Common examples include 'because,' 'since,' and 'for.' The lecture explains that these words can sometimes be used in non-premise contexts, as in 'since noon,' so it's important to understand the context in which they are used. This segment reinforces the need to be cautious when identifying premises based solely on indicator words.

🔑 Conclusion Indicators

Conclusion indicators, such as 'therefore,' 'so,' and 'hence,' are terms that signal a conclusion is being drawn. Just like with premise indicators, these terms can sometimes be used in non-argumentative contexts, like hesitation ('so... do you want to go out for lunch?'). The lecture provides examples of when these terms indicate a conclusion versus when they do not, encouraging careful reading of context.

📝 Exercise: Identifying Premises and Conclusions

In this exercise, the task is to identify the premises, conclusion, and indicators in a simple argument about Isabelle passing her Critical Thinking class. The word 'so' is identified as a conclusion indicator, and the two premises are 'People who study hard will pass' and 'Isabelle studies hard.' The conclusion is that 'Isabelle will pass Critical Thinking.' This exercise demonstrates that premises and conclusions can sometimes occur in the same sentence.

🔍 Summary of Key Learnings

The lecture concludes by summarizing the key points covered: arguments consist of statements, and statements can be identified by the 'It is true that' test. We learned how to identify premises and conclusions in arguments through the use of indicators. The lecture emphasizes the importance of these skills for understanding and evaluating arguments in critical thinking. The session ends with a thank you to the viewers.

Keywords

💡Argument

An argument is a set of statements where one statement, the conclusion, is supported by others, called premises. In the video, arguments are explained as a key part of reasoning, providing reasons for accepting a conclusion. An example from the script is the argument about the rain: 'It’s raining. If it’s raining, then it is wet outside. So, it is wet outside.'

💡Statement

A statement is a sentence or part of a sentence that asserts something to be the case. In the video, it’s highlighted that arguments are made up of statements. For example, 'Spot is a good dog' is a statement because it declares something as true. Statements form the foundation of arguments.

💡Premise

A premise is a statement that supports the conclusion of an argument. It provides the reasoning or evidence for why the conclusion should be accepted. In the example 'It’s raining. If it’s raining, then it is wet outside. So, it is wet outside,' the first two statements serve as premises for the conclusion.

💡Conclusion

The conclusion is the statement in an argument that the premises are meant to support. It is the final point that the argument aims to prove. For example, 'So, it is wet outside' is the conclusion in the argument about rain, as it is supported by the preceding premises.

💡Premise Indicator

A premise indicator is a word or phrase that signals the presence of a premise. Words like 'because,' 'since,' and 'after all' suggest that the following statement is a premise. For example, in 'Winter is coming. After all, it’s snowing,' the phrase 'after all' indicates that 'it’s snowing' is a premise supporting the claim 'Winter is coming.'

💡Conclusion Indicator

A conclusion indicator is a word or phrase that signals the conclusion of an argument. Words like 'therefore,' 'so,' and 'thus' are often used to introduce conclusions. For instance, in the example 'Isabelle studies hard, so she will pass,' the word 'so' indicates that 'she will pass' is the conclusion.

💡Declarative Sentence

A declarative sentence is another term for a statement—it declares something to be the case. The video contrasts declarative sentences with interrogative (questions) and imperative (commands). For example, 'Spot is a good dog' is a declarative sentence because it asserts a fact.

💡Interrogative Sentence

An interrogative sentence asks a question and does not assert something as true. The video explains that interrogative sentences cannot form part of an argument. For example, 'Is Spot a good dog?' is an interrogative sentence because it asks a question rather than stating a fact.

💡Imperative Sentence

An imperative sentence gives a command or instruction, and it does not form part of an argument. The video gives the example 'Be a good dog, Spot!' which is an imperative because it issues a command, not a statement. Imperative sentences cannot function as premises or conclusions.

💡Critical Thinking

Critical thinking refers to the skill of analyzing and evaluating arguments to understand and assess them. In the video, critical thinking is demonstrated through exercises like assessing whether premises support a conclusion. It emphasizes the importance of understanding arguments to evaluate beliefs or decisions rationally.

Highlights

Arguments are sets of statements, with one statement (the conclusion) supported by others (the premises).

The difference between statements and other expressions, like interrogative or imperative sentences, is that statements assert that something is the case.

A useful test to identify a statement is to append 'It is true that' to an expression; if the result is grammatical, it's a statement.

Premise and conclusion indicators help identify the structure of an argument, such as 'because' for premises and 'therefore' for conclusions.

An example of an argument: 'It’s raining. If it’s raining, then it is wet outside. So, it is wet outside.'

Premise indicators include words like 'because,' 'since,' and 'for,' while conclusion indicators include words like 'therefore,' 'so,' and 'hence.'

Interrogative sentences ask questions and imperative sentences give commands, both of which are not statements.

Statements are also referred to as declarative sentences because they declare something to be the case.

Even false statements like 'Elephants fly' are still considered statements because they assert that something is the case.

The purpose of arguments is to provide reasons for accepting a conclusion, rather than just stating what to believe.

An argument’s strength lies in whether the premises provide sufficient reason to believe the conclusion.

Premise indicators are not always present, and some words like 'since' or 'assuming' can function in ways that don’t indicate premises.

Similarly, conclusion indicators like 'so' or 'therefore' can be used in non-conclusion contexts, such as signaling hesitation.

The exercise example: 'People who study hard will pass Critical Thinking. Isabelle studies hard, so she will pass.' identifies 'so' as a conclusion indicator.

Identifying arguments in everyday language can be challenging, but understanding premise and conclusion indicators helps clarify the structure.

Transcripts

Hello, and welcome to lecture 2a:  

Identifying Statements and Arguments. This week, we will talk about arguments---that is,  

bits of reasoning---and how to analyze them---how  to understand what’s going on with them.  

This lecture explains what  arguments and statements are.  

We will learn how to tell the difference  between statements and other expressions.  

We’ll also learn how to identify the premises  and conclusions of arguments---and hence  

arguments themselves---using particular  words and phrases, which we’ll call  

“premise and conclusion indicators”. An argument is a set of statements,  

one of which (the conclusion) is supposed to  be supported by the others (the premises).  

Here’s an example of three statements  that make up an argument:  

It’s raining. If it’s raining,  

then it is wet outside. So, it is wet outside. What makes these statements an argument  

is that the first two statements are  supposed to support the last statement.  

Last week, we encountered this argument---an  argument for the claim that you should choose  

the major that interests you most. We talked  about how it works and how we might assess it.  

The exercise provided us an example of  our critical thinking skills at work.  

As illustrated by the previous  example, the purpose of arguments  

is to provide reason for accepting a conclusion.  

When you provide an argument to someone,  you don’t just tell them what to believe,  

but also why they should believe it. This is why understanding arguments is  

important. It helps us evaluate whether there  is in fact reason to believe a conclusion.  

Let’s look at our definition  of an argument again.  

According to the definition, arguments  are composed of statements.  

Statements are sentences or parts of sentences  that say that something is the case.  

For example, the sentence “Spot is a good dog” is  a statement. It says that something is the case,  

namely, that Spot is a good dog. The function of statements in  

language is to assert things––to  say that something is the case.  

Another term used for statements is “declarative  sentences”–––because these are sentences that  

“declare” something, that say  that something is the case.  

Statements can be contrasted  with two other kinds of sentences  

(or parts of sentences). Interrogative sentences  

(or parts of sentences) are sentences (or  parts of sentences) that ask a question.  

For example, “Is Spot a good dog?”  is an interrogative sentence.  

Imperative sentences (or parts of sentences)  are sentences (or parts of sentences)  

that issue a command. For example, “Be a good dog,  

Spot!” is an imperative sentence. Notice that interrogative sentences  

and imperative sentences––sentences that  ask questions or issue commands––don’t  

state that something is the case. They don’t  say that Spot is a good dog or that anything  

else is the case. Only statements do that. Okay, so what we’re interested in is statements,  

since statements are what make up arguments. That makes sense, since the whole point of an  

argument is to convince you that one thing  is the case based on other things being the  

case. Only statements can play the roles of being  what an argument is aiming to convince you of and  

what it is taking for granted, i.e.,  the roles of conclusion and premises.  

So, in order to identify arguments––in order  to know when we’ve encountered an argument––it  

helps to be able to identify statements.  

Here is a test that will tell you  whether an expression is a statement.  

If you’re not sure whether some expression––call  it φ (“phi”)––is a statement, try appending  

“It is true that” to the beginning of it. If “It is true that φ (phi)” is grammatical,  

then φ (phi) is a statement. For example, take the sentence “Elephants fly.”  

Add “It is true that” before it and see if the  result is grammatical. Since “It is true that  

elephants fly” is grammatical, the original  sentence, “Elephants fly” is a statement.  

Note that it doesn’t matter that the statement  is in fact false––it’s still a statement.  

What if we run the test on another  sentence: “Do you like ice cream?”  

We append “It is true that” to the  beginning of the sentence, giving us  

“It is true that do you like ice cream?” This is ungrammatical, so, using our test,  

we can tell that “Do you like  ice cream?” is not a statement.  

Now take the sentence “I like ice cream.” Let’s append “It is true that” to it, giving  

us “It is true that I like ice cream.” This is grammatical, so the sentence  

is a statement. Note that it doesn’t  matter that “I like ice cream” expresses  

an opinion. It is still a statement. It  still says that something is the case,  

namely, that I like ice cream. And I do. Yum. Okay, so now that we know what statements are,  

let’s go back to arguments. Again, an argument is a set of statements,  

one of which is supposed to  be supported by the others.  

Spotting or identifying arguments  in the wild can be challenging.  

You have to figure out whether some  statements are intended to support  

some other statement. There is no  foolproof mechanical way to do this.  

But there are expressions that suggest  that a statement is a conclusion or a  

premise in an argument. Here are some examples:  

The grass is healthy. Therefore,  it rained this past week.  

Here, the word “therefore” indicates that what  follows is the conclusion of an argument.  

Winter is coming. After all, it’s snowing. The words “after all” indicate that what  

follows is a premise of an argument. These phrases are premise and conclusion  

indicators––they flag statements  as premises or conclusions.  

We will say that premise indicators are  expressions that indicate a premise,  

and that conclusion indicators are  expressions that indicate a conclusion.  

Here are some examples of words and phrases  that often indicate that a premise follows:  

because, since, for, after all, first, second, etc.,  

firstly, secondly, etc., on the assumption that, assuming that,  

in view of the fact that, this follows from,  

this is shown/indicated/suggested/supported by,  

and this can/may be  inferred/deduced/derived from.  

Of course, this list is not exhaustive. There  are many other ways to signal a premise.  

Note that words that sometimes function as premise  indicators can occur in the absence of a premise.  

This is because they can also have other uses.  

For example, we can use ”since” to  say “I’ve been here since noon.”  

“Noon” is not a premise here and “since” is  not functioning as a premise indicator.  

Here’s another example: “I’m assuming  that you don’t want to go to lunch.”  

“You don’t want to go out to  lunch” is not a premise.  

“I’m assuming that” is not  functioning as a premise indicator.  

Here are some expressions which sometimes  serve as conclusion indicators:  

therefore, so, thus, hence,  consequently, in consequence,  

it follows that, this  

suggests/proves/demonstrates/entails/implies/shows  that,  

and as a result. Again, there are many  

other ways to indicate a conclusion. And, again, note that these expressions can be  

used in ways that don’t indicate a conclusion. For example, someone might use “so”  

to signal hesitation, as in “so…  do you want to go out for lunch?”  

In the online exercises,  you will sometimes be asked  

to identify premises, conclusions, and  premise and conclusion indicators.  

Let’s do an exercise together. Our task is to identify the premises  

and conclusion of the following argument, as  well as any premise and conclusion indicators.  

People who study hard will pass Critical Thinking.  Isabelle studies hard, so she will pass.  

Feel free to pause this video  to think about the exercise.  

Ready? Let’s start with a conclusion indicator.  

This is the word “so”. There are no premise indicators.  

Now let’s do the premises. The premises are:  

“People who study hard will  pass Critical Thinking”  

and “Isabelle studies hard.”  

And the conclusion is “Isabelle  will pass Critical Thinking.”  

Notice here that one of the  premises and the conclusion  

occur in the same sentence––that is okay.  

Let’s summarize what we’ve done. In this presentation, we saw that arguments  

are made up out of statements. We learned how to identify statements  

by appending “It is true that” to expressions  to see if the result is grammatical.  

We learned how to identify which statements  form parts of arguments by looking for  

premise and conclusion indicators. The end. Thanks for watching!