HZRT4U - Unit One: Logic and Reasoning Unit Test Review

Philosophy

• “The love of wisdom”

• Study of fundamental nature of knowledge, reality, and existence

• Begins in wonder

Aesthetics

The study of what is beautiful and what makes someone beautiful

Deductive Arguement

An arguement where conclusions are reached by reasoning

Valid Deductive Argument

The conclusion logically follows the premises

Invalid Deductive Argument

Conclusion does not logically follow the premises (premise3s are true but the conclusion is false)

Argument

The reasons that support a particular conclusion

Premise

A statement assumed to be true that is used to reach a conclusion

Conclusion

A decision, judgement, or opinion reached by reasoning

Syllogism

A three lined argument where the first two lines are premises and the third line is the conclusion

Inductive argument

• an argument in which the conclusion as a general rule is PROBABLY true, based on specific premises that are true

• There is always an assumption that the future observations will continue because the pattern that’s been established by past observations

Abductive Argument

An argument in which the conclusion is a “best guess” given the premises are true

Formal Logic

The study of deductive arguments

Proposition

A statement that is considered to be either true or false

Reasoning

The process of forming conclusions, judgements, or inferences from facts or premises

Law of Identity

• states that a thing can only be the same as itself

• Whatever a thing is, it is what it is, and cannot be something other than what it is

Law of Non-Contradiction

States that a proposition cannot be true and false at the same time in the same respect

Contradiction

Occurs when a proposition is held to be both true and false at the same time in the same respect

Excluded Middle

• States that a specific proposition is either true or false, with no middle ground

• The truth of a proposition can be contingent upon time, location, and definition of a term but the proposition itself is either true or false

Truth Value

The truth or falsity of a proposition

Principle of Sufficient Reason

States everything (wether its a thing, event, or proposition) must have a reason or a cause

Ockham’s Razor

Favours the simplest solution and uses the fewest entities to solve the problem

Logical Entailment

A relationship in which the conclusion must be true because the premises are true

Informal Logic

The study of arguments used in everyday contexts (not in a formal setting)

Cogent

Convincing of believable due to clear, strong reasoning

Fallacy

An argument that may seem to be cogent but proves upon examination, not to be cogent because it is based on faulty of incomplete logic

Hasty Generalization

A fallacy in which a general conclusion is made based on insufficient evidence

Principle of Charity

A belief that an Argument should be given its strongest interpretation

Categorical Syllogism

• 3 line deductive argument that uses 3 categorical terms that are each used twice

• Consists of propositions that categorize things by stating wether of not they belong in a certain category

Sound argument

The premises are true, and the argument is valid so the conclusion must be true (sound is not the same as valid)

Hypothetical Syllogism

3 line deductive argument where at least one of the premises is a conditional statement, the antecedent or consequent of which appears in the other premise

Modus Ponens

• a rule of inference used to draw logical conclusions

• If p is true, and if p implies 9, then q must be true

• Affirms the logic or truth of an argument

Modus Tollens

• Method of denying

• Rule of inference drawn from the combination of modus pollens and the contrapositive

• If q is false, and if p implies q, then p is also false

Main Periods in Philosophy (7)

• Classical Period

• Midevil Period

• Renaissance Period

• Enlightenment Period

• Early Modern Period

• Late Modern Period

• Contemporary

Why is good reasoning Important (5 reasons)

1. Make decisions

2. Avoid manipulation

3. Determine validity of information

4. Defend our position

5. Make sense of the world

What is Ockham’s Razor

Favours the simplest solution that uses the fewest entities to solve the problem

What are Francis Bacon’s four idols of the mind?

1. Idols of the tribe

2. Idols of the Cave

3. Idols of the Marketplace

4. Idols of the theatre

Idol of the tribe

biases we all have as humans

Idol of the cave

Biases we have that are unique based on our experiences, interests, and education

Idols of the marketplace

Biases that come from sloppy words

Idols of the theatre

Biases that come from blindly accepting society’s systems

Fallacies that focus on people (5)

1. Attack on the person

2. Appeal to tradition

3. Attack on the Motive

4. Bandwagon/appeal to popularity

5. Straw Man

Attack on the person

Attacking the arguer instead of attacking the argument

Appeal to tradition

We accept traditional practices just because they’re tradition

Attack on the Motive

The argument attacks the credibility of the person or group on the grounds that the group or person has ulterior motives or biases

Bandwagon/appeal to popularity

Appealing to the masses without considering wether its right

Straw Man

Misrepresenting a person’s argument making it seem weaker than it is so its easier to knock down

Fallacies that focus on structure (5)

1. Appeal to ignorance

2. Circular Argument

3. Equivocation

4. Loaded Term

5. Slippery Slope

Appeal to Ignorance

There is no evidence for the truth of p, so p is false

There is no evidence for the falsity of p, so p must be true

Circular Argument

When the argument’s premise assumes the truth of the conclusion

Equivocation

Using a term that has 2 different meanings in a way that presents the 2 meanings as one

Loaded Term

A term is loaded when it is used broadly or narrowly to drive a particular conclusion

Slippery Slope

When an argument attacks an action or policy because the action or policy would trigger a chain of events that would lead to a clearly undesirable result

Fallacies that focus on specific-general and part-whole relationships (4)

1. Accident

2. Hasty Generalization

3. Composition

4. Decomposition

Accident

Occurs when exceptional or accidental factors are overlooked while arguing that a general rule should be applied

Hasty Generalization

Occurs when an atypical situation is used to undermine or argue for a general rule while overlooking atypical or accidental features of the situation

Composition

Occurs when the features of the parts are erroneously assigned to the whole

Decomposition

Occurs when a feature of the whole is erroneously ascribed to the parts