PHIL102: Introduction to Critical Thinking and Logic

1a. Distinguish between the literal and implied meanings of sentences

• What is literal meaning?
• What is conversational implicature?
  
• Why is the distinction between the literal and implied meanings of sentences important to clear thinking?

A sentence's grammatical structure and the conventional meanings assigned to the words used constitute literal meaning. More specifically, literal meaning is a property of linguistic expression; to understand the meaning of that expression in literal terms is to understand the common meaning of each word in the expression, along with that expression's grammatical structure. The common meaning of a word is typically found in a dictionary or colloquial usage. Grammatical structure, in turn, is a sentence's arrangement of elements – words, clauses, or phrases.

A sentence's literal meaning is often only a part of a more sophisticated communication process. In various exchanges, a sentence's literal meaning is not intended as the exclusive communication. A sentence takes on new meaning in the larger context of a conversation. Conversational implicature is the term for the implicit meaning a sentence conveys in the context of a conversation.

The distinction between literal and implied meaning, then, is between what a sentence asserts and what that sentence implies in the larger context of a conversation. It is important to understand this distinction, as confusion often results from glossing over it. Moreover, the truth or falsity of the sentence implied, but not explicitly stated, isn't properly determined until made explicit.

Think about it this way, which brings us closer to the core of a course like this, namely inference-making: The sentence uttered is, in the context of a conversation, often used as an indication of an inference implied but not stated. Let's take one of the examples from the text (Literal Meaning): Upon being asked if she wants to go to the movies, Lily replies, "I am very tired". Given the context of the conversation, we conclude that Lily doesn't want to go. Absent the context, there is no specific inference to draw. Suppose, apropos of nothing, Lily asserts, "I am very tired", we'd have a hard time knowing what inference to draw. The truth or falsity of the implied sentence, "Lily does not want to go to the movies", depends on the evidence we have. The reasoning could look like this: If Lily wants to go to the movies, then she isn't very tired. But she is very tired. So, she doesn't want to go to the movies".

To review, see Meaning Analysis: Literal Meaning.

 

1b. Describe reportive, stipulative, precising, and persuasive definitions, and apply them to real-world scenarios

• What is a reportive definition?
• What is a stipulative definition?
• What is a precising definition?
• What is a persuasive definition?

How we define words contributes to meaning, clarity, and good reasoning. Consider, for example, the different ways measurements are defined, such as inches, milliliters, circumference, or area. Four of the most common definition types are reportive, stipulative, precising, and persuasive. Let's take a look at each.

A reportive definition simply reports the current meaning of a term. Also known as a lexical definition, reportive definitions provide us with the correct usage of a term. Consequently, when defining a technical term or difficult to define words, a properly reportive definition goes beyond the limitations of what a dictionary allows. That's because a standard dictionary simply cannot capture the scope or technical meaning of every term. For example, while "cat" is somewhat successfully defined as "a four-legged furry animal", it's not comprehensive; there are four-legged furry animals that are not cats. The relation between a term and its definition, in this case, does not tell us exactly what a cat is.

A stipulative definition assigns a new meaning to an existing term. We often stipulate a definition for the purpose of moving forward in a discussion or debate – there is a specific purpose for the definition. It can be an efficient way to facilitate the scope or domain of the communication. So, for example, one can say, "Let's stipulate that 'DOA' means Department on Aging, not Dead on Arrival".

A precising definition does what it says, namely it makes a vague or ambiguous definition more precise, thereby avoiding or clearing up confusion (and erroneous inferences). This precision might be considered combining the reportive and stipulative definitional processes. In a given context, for example, we might want to generate a precising definition of "energy". So, a patient might describe feeling a lack of energy, which could mean fatigue, lethargy, and so forth. A precising definition can help the doctor hone in on a medical explanation.

A persuasive definition is used with the intention of influencing, positively or negatively, typically by way of emotional or figurative language. Typically, persuasive definitions of a term are not the literal meaning. When engaging in argumentation, we should avoid this type of definition.

To review, see Meaning Analysis: Definitions.

 

1c. Describe the criteria for evaluating definitions and sources, and apply them to real-world scenarios

• What are some criteria for evaluating definitions?
• What are some criteria for evaluating sources?

Each type of definition has its own evaluation criteria. So, a reportive definition of a term is good if it accurately reflects the current usage of that term. A reportive definition accurately reflects the current usage of a term if it is neither too broad nor too narrow.

A definition that is too broad includes things it should not. Consider the previous poor definition of "cat" as "a four-legged furry animal". The definition is too broad because it includes animals such as mice. On the other hand, a definition that is too narrow excludes things it should not. For example, "cat" means "lion" excludes other felines. There are some definitions that fail both criteria at once. For example, "cat" is "a furry animal that roars".

Because stipulating a definition means offering a new meaning for a term, a stipulative definition does not fail in the same ways a reportive definition can fail, namely, they cannot be either too broad or too narrow. It can, however, be circular, inconsistent, or obscure.

A circular definition simply defines the term in question with the very term itself. It does not provide information that expands our understanding. To stipulate "painkiller" as "that which kills pain" does not provide new information.

A stipulative definition that is inconsistent presents incompatible ideas. So, defining "cat" as "a creature that meows but is silent", is inconsistent. An obscure stipulative definition is unclear. For example, defining "sprint" as "a short race" is unclear, since "short" is vague.

To review, see Meaning Analysis: Evaluating Definitions.

 

1d. Distinguish between factual disputes and verbal disputes

• What is a factual dispute?
• What is a verbal dispute?

A dispute is a disagreement. Those disputes we tend to think are worth resolving involve facts – determining the facts of the matter. We make claims that we believe are true, that is, that reflect a fact or set of facts. For example, if Person A believes they left their keys on the dining table, but Person B believes the keys were left in the car. Their dispute is factual, specifically, it's a dispute about the location of the keys.

Sometimes, however, we believe we're engaged in a factual dispute, but instead, we're essentially speaking at cross-purposes, which generates linguistic misunderstanding. This happens when the words or phrases we use are vague or ambiguous. Each party has a different understanding of the words or phrases, and so the dispute is not over facts. This is a verbal dispute.

We might go so far as to say there is no dispute at all, since the two parties aren't talking about the same thing! Depending on how each party defines the term in question, the misunderstanding, and so dispute, arises. If at least one of the individuals involved realizes that they need to either stipulate a definition or work on a more precise definition, either the dispute will dissolve, or they'll have a better shot at disagreeing over the facts. So, for example, if Person A asserts, "All humans are equal", and Person B retorts, "No way! DNA is unique", it's clear that each has a different understanding of "equal".

To review, see Meaning Analysis: Verbal Disputes.

 

1e. Define necessary and sufficient conditions, and give examples of each

• What is a necessary condition?
• What is a sufficient condition?
• What are some examples of a necessary condition?
• What are some examples of a sufficient condition?

A necessary condition is what must be the case for something else to obtain. For example, oxygen is a necessary condition for fire. In other words, without oxygen, fire does not obtain.

Oxygen does not guarantee fire, so it is not a sufficient condition. A sufficient condition guarantees an event. For example, earning a 95% on an exam is sufficient for an A (assuming a standard grading scale). Another way to put it is that earning a 95% guarantees an A.

Notice that conditions can be natural (as the oxygen example illustrates) or conventional (as the grade example illustrates). In either case, how we word the relation between necessary and sufficient conditions is important. A standard formulation is the conditional claim ("if…then"). The actual or supposed (or claimed) sufficient condition goes after "if", that is, in the antecedent position. The actual or supposed necessary condition goes after "then", or in the consequent position. Here are examples, some of which exhibit actual conditions, and some of which exhibit supposed conditions:

• If it is a dog, then it is an animal.
  • Being a dog is sufficient for being an animal.
  • We can also say that without "it" being an animal, it can't be a dog.
  • So, the claim that being a dog is a sufficient condition, and that being an animal is a necessary condition.
• If it is an animal, then it is a dog.
• Being an animal does not guarantee that animal is a dog.
• It's also not the case that without "it" being a dog, it's not an animal.
• So, the claim that being an animal is a sufficient condition for being a dog is false, as is the claim that being a dog is a necessary condition for being an animal.
• If it flies, then it's a bird.
• Something that flies may or may not be a bird.
• So, being a flying thing does not guarantee that thing is a bird.
• Not being a bird does not prevent something from flying.
• So, neither the sufficient nor necessary conditions are met in this claim.
• If it's a bird, then it flies.
• Being a bird does not guarantee flight – penguins are birds, but don't fly.
• Similarly, not being a flying thing does not thereby prevent that thing from being a bird.
• So, neither condition is met in this claim.
• If there is fire, then there is oxygen.
• Fire guarantees there is oxygen, as oxygen is necessary for fire.
• Without oxygen, there is no fire.
• Where there is fire, there must be oxygen. Both conditions are met in this claim.
• If there is oxygen, then there is fire.
• Oxygen does not guarantee fire. There are lots of places where there is oxygen without fire.
• Similarly, a lack of fire does not yield a corresponding lack of oxygen.
• Neither condition is met in this claim.

In Unit 3, we learn that the logical structure of a conditional claim is such that an affirmation of the antecedent yields the consequent. A denial of the consequent yields a denial of the antecedent. So, consider the following argument:

If there is oxygen, there is fire. It's not the case that there is fire. So, it's not the case there is oxygen.

We know that oxygen is not sufficient for fire. We also know that fire is not necessary for oxygen. What we know, however, is not relevant to the conditional claim's logical structure. Recall, however, the previous discussion about what we claim to be the case vs. what is the case. Whether or not a claim is true is distinct from the logical structure of that claim!

To review, see Necessity and Sufficiency.

 

1f. Evaluate statements for various types of obscurity, such as lexical ambiguity, referential ambiguity, syntactic ambiguity, vagueness, incompleteness, and meaning

• What is an obscure sentence?
• What is lexical ambiguity?
• What is referential ambiguity?
• What is syntactic ambiguity?
• What is vagueness?
• What is incompleteness?

An obscure sentence is unclear. There are several ways in which a sentence reflects a lack of clarity. It can be ambiguous, vague, or incomplete. Moreover, there are several ways in which a sentence can be ambiguous. An ambiguous sentence is one in which multiple meanings are possible because a word in the sentence has multiple meanings. In addition, sentences can be unclear due to vagueness or incompleteness.

A sentence in which a single word with multiple meanings is not used precisely for the context is called lexical ambiguity. Consider the sentence, "They saw bats". "Bat" has at least two meanings: an object used to hit a ball and a (mostly) nocturnal mammal with wings. Because the sentence does not specify which meaning is intended, one could draw at least two inferences.

A sentence in which a single word does not explicitly refer is referentially ambiguous. For example, the sentence, "Person A and Person B got into the car and they turned on the air conditioning". It's not clear which person turned on the air condition, since "they" is ambiguous – it can equally refer to Person A or Person B.

A syntactically ambiguous sentence's grammatical structure is unclear. Consider the sentence, "Politicians are frightening people". It is unclear if people are being frightened by politicians, or if politicians, as a group of people, are frightening.

Vagueness differs from ambiguity in that an ambiguous word has multiple, but still determinate meanings, while vague language is indeterminate. Words 'carve out' meaning, which, as we've seen, should be as precise as possible for effective communication. When communication is inexact, misunderstanding and muddled reasoning can follow. Consider this exchange:

Suppose that Person A wants a timeframe, so as not to be late for dinner. Person B's response is vague. What does "in a while" mean in this context? A determinate time (e.g., 15 minutes) would eliminate the vagueness in the original response.

Another way in which words can yield a vague sentence is when they contribute to an incompletely expressed idea. Here again, context matters. When we find ourselves filling in conceptual gaps, for example, we should thereby be alerted to an incompletely expressed idea. We find ourselves asking, "In what way?" or "But how?" Consider the example from Slide 12: "Will this year's final exam be similar to the one last year?" We should find ourselves asking, "In what way is this year's final exam potentially similar to last year's? Are we talking about content, format, number of questions, or difficulty level?"

To review, see Thinking Critically About Ordinary Language: Obscurity.

 

1g. Evaluate statements for distortions of meaning, such as reification, category mistakes, and poor philosophical argumentation

• What is distortion?
• What is reification?
• What is a category mistake?
• What is poor philosophical argumentation?

Related to persuasive definitions, distortions of meaning can result in an erroneously positive or negative disposition. As we will see in Unit 5, where we cover informally fallacious (erroneous) reasoning, the intentional distortion of meaning is associated with a failure to seek truth. Suppose, for example, someone – we'll call them Person A – has concluded that euthanasia is morally wrong. That person then engages in conversation with someone – we'll call them Person B – who either does not think euthanasia is morally wrong, or is undecided. Person A asserts that euthanasia is murder and, as such, should not be legalized. While Person 1 may not believe they have distorted the meaning of euthanasia, it's clear that the morality of euthanasia is not a settled matter. In purely descriptive terms, the meaning of euthanasia does not include unjustified killing, which is how we generally understand "murder".

Another way in which language can distort is through reification. To reify is to make a concrete thing out of an abstraction. Consider the iconography of justice, which is typically exhibited, in the Western tradition, by a woman holding up a scale. The icon is an embodiment not intended to substitute for the concept, but if we did so, we would have reified justice.

To make a category mistake is a specific instance of reification. Consider two categories, apples and oranges. Apples are fruits and oranges are fruits, but only one is a citrus fruit. Were we to 'place' apples in the citrus fruit category, we would have miscategorized it. Citrus is not a property of apples.

The phrase, "category mistake" was coined by Gilbert Ryle in a famous philosophical critique of Descartes's claim that mind and body are two distinct kinds of substance – mind is an immaterial substance, and body is a material substance. According to Ryle, Descartes erroneously places "the mind and body in the same logical type or category when they actually belong to another". See The Concept of Mind (Routledge, 1949).

There are multiple ways in which argumentation can go wrong – indeed, this course involves studying some of the most important argumentation failures. Poor philosophical argumentation – any argumentation, really – occurs most blatantly when the arguer distorts, rather than investigates in search of truth.

To review, see Thinking Critically About Ordinary Language: Distortion.

 

Unit 1 Vocabulary

This vocabulary list includes the terms listed above that you will need to know to successfully complete the final exam.

• antecedent
  
• category mistake
• consequent
• conversational implicature
• distortions of meaning
• factual dispute
• implied meaning
• incompletely expressed idea
• lexical ambiguity
• literal meaning
• necessary condition
• obscure
• persuasive definition
• precising definition
• referentially ambiguous
• reification
• reportive definition
• stipulative definition
• sufficient condition
• syntactically ambiguous
• vagueness
• verbal dispute