Kreeft Intro Chapter part 2

Question 1

A term has no structural parts. What is a term?

(text p. 29)

Answer 1

-is a basic unit of meaning, similar to the way that the number one iis a basic unit in math

when we say a term doesn’t have structural parts, were saying it doesn’t have a subject and a predicate. A proposition and an argument will have subjects and predicates, and an argument will have premises and conclusions. However, a term does not have a subject or predicate.

Question 2

Describe the composition of a proposition.

Answer 2

a proposition has two structural parts: the subject term and the predicate term

The subject term is what you’re talking about.
the predicate term is what you say about the subject.

Question 3

Describe the composition of an argument.

(text p. 29)

Answer 3

has two structural parts: the premises and the conclusion

The premises are the propositions that are assumed
premises are the reasons or evidence for the conclusion

The conclusion is the proposition that you’re trying to prove. it’s what you try to get your listener to accept or believe.

Question 4

look at this statement:
“All men are mortal, and I am a man, therefore I am mortal.”
What is the argument?

(text p. 30)

Answer 4

the argument is everything inside the quotation marks. In other words, every word in this statement is the actual argument.

Question 5

look at this statement:
“All men are mortal, and I am a man, therefore I am mortal.”
What are the two premises?

(text p. 30)

Answer 5

here are the two premises:

All men are mortal
I am a man

subject of the first premise = men
predicate of the first premise equals mortal

subject of the second premise = I
predicate of the second premise = a man

The subject term is what you’re talking about; the predicate term is what you say about the subject

Question 6

look at this statement:
“All men are mortal, and I am a man, therefore I am mortal.”
What is the conclusion?

(text p. 30)

Answer 6

conclusion: I am mortal

subject of the conclusion = I
predicate of the conclusion = mortal

The subject term is what you’re talking about; the predicate term is what you say about the subject

Question 7

What are the structural parts of an argument?

(text p. 30)

Answer 7

an argument will have a first premise, the second premise, and a conclusion

The first premise must have a subject term and a predicate term.
The second premise must also have a subject term and a predicate term.
The conclusion must have a subject term and predicate term.

Again, the argument will have a first premise, second premise, and a conclusion. Each of these individual parts must have a subject term and a predicate term.

Question 8

The three key logical entities are term, proposition, and argument. They each answer a different question. What question does each logical entity answer?

(text p. 30)

Answer 8

The three logical entities are term, proposition, an argument.
term: answers the question what it is
proposition: answers the question whether it is
argument: answers the question why it is

Question 9

The three key logical entities are term, proposition, and argument.
Look at this statement: because man is an animal, and all animals are mortal, therefore man is mortal.
What is the term?
What is the proposition?
What is the argument?

(text p. 30)

Answer 9

term: man
-a term answers the question what it is; in this case, the term into the question what are we talking about

proposition: that man is mortal
proposition answers the question whether something is a particular way; in this case proposition tells us what we are saying about man. We are saying that man is mortal.

Argument:”because man is an animal, all animals are mortal, therefore man is mortal.”

An argument answers the question why something is a particular way. In this case, we are answering the question of why is man mortal.

Question 10

The three key logical entities are term, proposition, and argument. They each reveal different aspects of reality.

What aspect of reality do terms reveal?

Answer 10

terms reveal the essences something; they tell you what a thing is

Question 11

The three key logical entities are term, proposition, and argument. They each reveal different aspects of reality.

What aspect of reality do propositions reveal?

(text p. 30)

Answer 11

propositions reveal existence; they say whether it is a particular characteristic, a particular state, etc.

Question 12

The three key logical entities are term, proposition, and argument. They each reveal different aspects of reality.

What aspect of reality do arguments reveal?

(text p. 30)

Answer 12

arguments reveal causes-they indicate why it is

Question 13

Logic has been described as practical art as well as a theoretical science. The practical art of logic consists in discriminating between:
——— versus ——————– terms
——— versus ——————– propositions
——— versus ——————– arguments

(text p. 30)

Answer 13

the practical art of logic consists in discriminating between:
clear versus unclear/ambiguous terms
true versus false propositions
logically valid versus invalid arguments

Question 14

Logic has been described as practical art as well as a theoretical_——–

(text p. 30)

Answer 14

science
logic:
-tells us what is and also what should be
-reveals the three fundamental logic structures ( terms, propositions, arguments) , judges them, and tries to improve the

Question 15

terms are only either ———– or —————

(text p. 31)

Answer 15

terms can only be described as clear or unclear

Terms are never true or false; instead, the propositions they are in our true or false

Terms are never valid or invalid; instead, only arguments are valid or invalid

Question 16

propositions are only either ————— or ——————

(text p. 31)

Answer 16

propositions can only be either true or false

Propositions are never clear or in clear; instead, the terms in them are clear unclear

Propositions are never valid or invalid; instead, the arguments they are parts of our either valid or invalid

Question 17

arguments can only be either ————- or ———————

(text p. 31)

Answer 17

arguments can only be valid or invalid

Arguments are never clear or unclear; instead, each of the terms in an argument is clear and clear

Arguments are never true or false; instead, each of the two propositions in an argument will either be true or false

Question 18

most of logic consistent deciding when an argument is valid. What criteria must be met in order for an argument to be logically valid?

(text p. 31)

Answer 18

it’s conclusion necessarily and must follow from its premises

In other words, if the premises are all true, then the conclusion has to also be true in order for the argument to be valid

example

Premise one: all men are mortal
premise two: I am a man
argument: All men are mortal, and I am a man; therefore, I am mortal.

Question 19

describe an invalid argument

(text p. 31)

Answer 19

an invalid argument happens when the conclusion doesn’t necessarily follow from the premises, even if the premises are true

Example
premise one: all men are mortal
premise two: all pigs are mortal
argument: all men are mortal, and all pigs are mortal; therefore, all pigs are men

Both premises are true, but the argument does not follow from the premises, and the conclusion is false therefore the argument is not valid.

Question 20

look at the following argument:
premise one: all men are mortal.
Premise two: Socrates is mortal.

argument: All men are mortal, and Socrates is immortal. Therefore, Socrates is a man.
Is this argument valid?

(text p. 31)

Answer 20

no, it is not valid.
The conclusion is valid.
Each premise is valid.
The problem is that the conclusion doesn’t follow the premises.

Notice that both premises defined something as mortal; they’re both true.
The conclusion, however, doesn’t talk about anything being mortal. Instead, it talks about something being a man.
The premises and the conclusion are addressing two completely different subjects.
the conclusion is factually correct also, but being a mortal is not the same thing as being a man.
This is an example where conclusion is factually correct, but the argument itself is invalid.

Question 21

let’s look at this argument:
I exist.
And grass is green.
Therefore Antarctica is cold.

What can we say about the premises?
What can we say about the argument?

(text p. 32)

Answer 21

Both premises are true.
the first premise and the second premise have nothing to do with each other.
Conclusion is factually correct, but it doesn’t have anything to do with either the first or the second premise. The conclusion does not follow from both the first and the second premise. Instead, the conclusion has nothing to do with either the first or the second premise.
Therefore, the argument is not valid.

Question 22

describe the only kind of argument that is useful.

(text p. 33)

Answer 22

-must have true propositions
-must be logically valid

Question 23

What must happen in order for us to know that a conclusion must be true?

(text p. 33)

Answer 23

-argument has clear terms
-argument has true premises
-logic is valid

All three conditions must be present in order for the conclusion to be true
if one or more of the above is lacking, we don’t know if the conclusion is true or false, so it has to be described as uncertain

Question 24

logic gives us rules for deciding when an argument is —– or —-.

(text p. 33)

Answer 24

valid versus invalid

Question 25

logic gives us ways to define terms so as to make them ____

(text p. 33)

Answer 25

Clear and unambiguous

Question 26

if we want to have critical, logical thinking, what three questions must be asked of ourselves when speaking or writing, and must we ask of others when listening or reading?

(text p. 33)

Answer 26

What do you mean? Define your terms.
What’s the point? In other words, what’s your conclusion?
Why? Prove it.

When you evaluate your own work this way, and you evaluate the work of others using these three questions, you are improving your critical thinking and logical thinking.

Question 27

if you want to make an on answerable argument, meaning you want to present something that cannot be refuted, what three conditions must you do so that you are proving your conclusion according to the rules of logic?

(text p. 34)

Answer 27

• be sure your terms are clear
  -be sure your premises are true
  -be sure your logic is valid

if you do all three things well, then you have proved your conclusion.

Question 28

if you want to answer someone else’s argument, meaning you want to suggest to them that there is something about it which is not valid, what are the three errors that you must look for? You have to find at least one of them to be able to assert that there argument is not valid.

(text p. 34)

Answer 28

-a term used ambiguously
-a false premise
-a logical fallacy, an invalid argument, or a conclusion that doesn’t necessarily follow from the premises

If you can’t find any of these three, then their conclusion is accepted as true.

Question 29

when we talk about validity of an argument, what do we mean, according to the slide discussed during the lecture?

See slide 24

Answer 29

validity refers to whether the argument follows proper form

An argument doesn’t have to be true in order to be valid ( understand that in this context, when we say valid, we mean that the argument has proper form and were not referring to whether or not the words being used in the argument are factually correct)

Question 30

what is soundness of an argument?

Slide 24

Answer 30

sound this means that an argument is valid and also true

Question 31

slide 25 discussed characteristics of deductive reasoning and inductive reasoning

describe these basic characteristics of deductive reasoning:

starts with given ________________ or ________________

is judged as either ________________ or ________________

deals with ________________

Answer 31

starts with given propositions, scientific theories, or axioms/postulates

is judged as either valid or invalid

deals with certainty

Question 32

slide 25 discussed characteristics of deductive reasoning and inductive reasoning

describe these basic characteristics of inductive reasoning:

starts with _______________

is judged as either ________________ or ________________

Deals with _______________

Answer 32

starts with observation/evidence

is judged as either strong or weak

Deals with probability

look at the examples on the next few slides which follow slide 25, and be able to tell if somebody is using deductive reasoning versus inductive reasoning.

Question 33

what is categorical logic?
( slide 41 )

Answer 33

looks at how an individual noun or term represents a category of things

uses to be verbs to connect building blocks

Question 34

what is propositional logic?

( slide 41 )

Answer 34

looks at how sentences ( propositions) relate to other propositions

uses logical operator words to connect building blocks

Question 35

All people should be compassionate beings.
I am a person.
Therefore, I should be compassionate being.
What kind of logic is this?

see slide 42

Answer 35

categorical logic

Question 36

if I want to improve the world, I should help my neighbor.
I want to improve the world.
Therefore, I will help my neighbor.

What kind of logic is this?

see slide 42

Answer 36

propositional logic