Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
79 Cards in this Set
- Front
- Back
Logic
|
-the organized body of knowledge, or science that evaluates arguments
|
|
What is the aim of Logic?
|
- to develop a system of methods and principles that we may use as criteria for evaluating the arguments of others and as guides in constructing arguments of our own.
|
|
Argument
|
- group of statements, one or more of which (the premises) are claimed to provide support for, or reasons to believe, one of the others (conclusions).
|
|
Two Groups of Arguments
|
- Premises support conclusion (good arguments)
- Premises don’t support conclusion (bad arguments) |
|
Purpose of Logic
|
-Distinguish between bad and good arguments
|
|
An Argument is a group of _________
|
- Statements
|
|
Statement
|
- Sentence that is either true or false (typically declarative)
|
|
Tiger Woods plays golf and Mos Def learned to rap from Vanilla Ice. (State the amount of statements and truth value)
|
- 2 statements
- last statement was false |
|
Truth Value
|
- truth or falsity
|
|
Types of Sentences that are not Statements
|
- (question)
- (proposal) -(suggestion) - (command) - (exclamation) |
|
Premises
|
-Statements that are set forth the reasons or evidence
Premises ==+> Conclusion |
|
Conclusion
|
- statement that the evidence is claimed to support or imply
|
|
All humans are animals.
Clay Matthews of the Packers is a human. Therefore Clay Matthews of the Packers is an animal. Number of Statements? Number of Premises? |
- 3 statements
- 2 premises |
|
Conclusion Indicators
|
Therefore, wherefore, thus, consequently, we may infer, accordingly, we may conclude, it must be that, for this reason, so, entails that, hence, it follows that, as a result
|
|
Premise Indicators
|
Since, as indicated by, because, for, in that, may be inferred from, as, given that, seeing that, for the reason that, inasmuch as, owing to
|
|
Break down
Expectant mothers should never do recreational drugs, since the use of these drugs can jeopardize the development of the fetus. |
2 Statements
Premise indicator:: “since” P:: since the use of these drugs can jeopardize the development of the fetus C:: Expectant mothers should never do recreational drugs |
|
“for reason that” vs. “for this reason”
|
Premises vs. conclusion indicator
|
|
Tips for when there are no indicator words present…
|
- what is the main point of the passage?
-what is the arguer trying to prove? -what single statement is claimed (implicitly) to follow from the others? |
|
Guide for Reconstructing Arguments
|
- Close as possible to the original version
- Premises and conclusion be complete sentences and meaningful in order in which they are listed -compound arrangements of statements in which various components are stated to be true are considered separate statements (in section 1) |
|
Statements not intended to support the conclusion or act as a conclusion should not be considered in the analysis of the argument
|
-introductions and passing comments … counter critque…. should not be considered apart of the premises
|
|
Inference
|
-narrow sense: reasoning process expressed by an argument
-broad: interchangeable with argument |
|
Proposition
|
- narrow sense:: meaning or information content of statement
- Interchangable with proposition and statement |
|
Father of Logic
|
Aristotle
|
|
What seperates Aristotle from his predecessors?
|
- devised systematic criteria for analyzing and evaluating arguments
-developed syllogistic and modal logic |
|
Syllogistic Logic
|
- terms are fundamental elements
-arguments evaluated to good or bad depending on how terms are arranged |
|
Modal Logic
|
- logic involves concepts such as possibility, necessity, belief, and doubt
|
|
Two conditions for a passage to purport to prove something
|
1. a t least one statement claiming to present evidence
2. claim that follows from alleged evidence |
|
Do premisies need to present actual evidence or true reasons?
|
NO.... it must CLAIM to present evidence or reasons ... there must be a claim or reasons to imply something
|
|
Inferential Claim
|
- simply a claim that the passage expresses a certain type of reasoning process
(that sumething supports or implies something or that somethign follows from something) -objective feature os an objective feature of an argument grounded in its language or structure |
|
why are intentions not relevant in analyzing an inferential claim?
|
-Because an inferential claim is objective
-intentions are subject in nature and usually are not accesible to the arguer |
|
Types of inferential CLaims
|
Implicit or explicit
|
|
Explicit Inferential Claim
|
- usually asserted by premise or conclusion indicator words (thus, since, because, therefore, hence, etc...)
|
|
What do conclusion indicator words do in terms of arguemnts
|
Express that something is to be inferred
|
|
Implicit Inferential Claim
|
- exists if there is an inferential relationship but the passage contains no indicator words...
|
|
Simple Noninferential Passages
|
-Warning
-Piece of Advice - Statement of Belief/ Opinion -Loosely Associated Statements -Report -Unproblematic passages that lack calim of anything being proved -Passages may have statements that could be premises or conclusions but lack a claim that any potential conclusion is supported by premises |
|
Warning Passage
|
-Noninferential Claim
-intended to put someone on gaurd ex "watch out so you don't slip" no evidence to prove that such statements are true, no argument |
|
Piece of Advice
|
-Noninferential Claim
- reccomendation for the future -You should keep a few things in mind before buying a car. test drive teh car. - there is no evidence that is intended to prove anthing ... no arguement |
|
Statement of Belief/ Opinion
|
-Noninferential Claim
-expression about what someone happends to think or believe ex " we believe that our friends are better than yours. We believe our friends are caring. " -no claim is made that his or her belief or opinion is suproted by evidence or that it supprots the conclusion |
|
Essential to an arguement is....
|
-conclusion that follows from premises that claim to evidence for conclusion
|
|
Loosely Associated Statements
|
-Noninferential Claim
- statement about the same general subject that lack claim that oneproves another |
|
Report
|
-Noninferential Claim
-group of statements that convey information about the same topic or event -often their are premises and even a squential flow to information but no claim is delivered.. none of the statements act as evidence in a struturally valid casual relationship that implies a process of reasoning -Reports might contain arguements such as in direct quotes but given that the author does not make a claim directly it is recognized as a passage with an argument in it not an argument in itself |
|
Expository Passages
|
-Noninferential Claim
- Topic sentece that is expounded - "flesh out an idea" -"show how" vs "prove that" |
|
Illustration Passages
|
-Noninferential Claim
-intended to show what someting means or how it is done - they do not claim anything is being proved |
|
Arguements from Example
|
- example to prove a claim
- typically claims are not common knowledge |
|
Explainations
|
-Noninferential Claim
- expression that purports to shed light on some even tof phenonmenon |
|
Two parts of Explanation
|
Explanas (claims that shed light on something)
Explanadum (Accepted fact) -"showing why" vs. "proving that" |
|
Conditional Statement
|
- an "if... then" statement what contains an antecedent and consqeuent
-not an arguement because it fails to have a statement taht claims to present evidence for another - no assertion that either antecedent or consquent is true -Premises in an arguement are claimed to be true -inferential content of conditional statements can often be rewritten as infrential arguments |
|
3 Rules for relating conditional statement to arguments
|
1. A single conditional statement is not an argument
2. A conditional statement may serve as either the premise or the conclusion of an argument 3. The inferential content of a conditional statement may be reexpressed to form an argument |
|
Necessary and Sufficient Conditions
|
-A necessary condition of a statement must be satisfied for the statement to be true
A sufficient condition is one that, if satisfied, assures the statement's truth |
|
Deductive Argument
|
- is an argument incorporating the claim that it is impossible for the conclusion to be false
given that the premises are true |
|
Inductive Argument
|
- an argument incoporating the claim tht it is impropable that the conclusion be false given that teh premises are true
-probabilistic reasoning |
|
Inductive vs Deductive
|
-Improbable vs Impossible
|
|
Objective Features of an Argument to determine it to be Inductive or Deductive
|
1. the occurence of special indicator words
2. actual strength of the inferential link between premises and conclusion 3. for or style of argumentation |
|
Special Indicator Words
|
- Inductive Indicators :: probable, improbable, plausible, implausible, likely, unlikely and reasonable to conclude
Deductive Words:: certainly, absolutely, definitely ((it must be the case is a conclusion indicator that can appear in either arguments)) |
|
Forms of Deductive Arguments
|
- mathmatics
- definition - categorical - hypothetical - disjunctive syllogisms |
|
Argument Based on Mathmatics
|
depends on purely arithmetic or geometric computation or measurement
- all arguements based on pure mathmatics are deductive ((exception /// statistics)) |
|
Argument from Definition
|
- Conclusion is claimed to depend merely on the definition of some word or phrase used in the premise or conclusion
|
|
Syllogism
|
-Argument consistenof exactly two premises on one conclusion
|
|
Categorical Syllogism
|
- a syllogism in which each statement begins with on of the words "all," "no," or "some"
|
|
Hypothetical Syllogism
|
- syllogism having a conditional statement for one or both of its premises
|
|
Disjunctive Syllogism
|
- having a disjunctive statement ("either ... or" statement)
|
|
Disjuntive Definition
|
1. Serving to separate or divide.
2. Grammar Serving to establish a relationship of contrast or opposition. The conjunction but in the phrase poor but comfortable is disjunctive. 3. Logic a. Of a proposition that presents two or more alternative terms. b. Of a syllogism that contains a disjunction as one premise. n. Grammar |
|
Inductive Forms
|
content of the Con. is in come was intended to "go beyond" the content of the Pres...
-Predictions about the future -Arguments from analogy -Inducitve Generalizations - Argu. from authority - Argu. based on signs - Casual inference |
|
Prediction
|
- argu. that proceeds from our knowledge of the past to a claim about the future
- whenever an argument is arguing the future that argument is inductive |
|
Argu. from Analogy
|
- is an argu. that depends on the existenceof analogy, or similarity, between two things or states of affairs
|
|
Generalization
|
- an argu. that proceeds from the knowledge of a selected sample to some claim about the whole group
|
|
Argu. from Authority
|
- an argument that concludes something is true becase a presumed expert or witness has said that it is
|
|
Casual Inference
|
- procedes form knowledge of a cause to a claim about an effect conversely from knowledge of an effect to a claim about a cause
-because specific instances of cause and effect can never be known with absolute certainty, one may usually interpret such arguments as inductive |
|
Complete certainty
|
deductive
|
|
Probablistic Reasoning
|
inductive
|
|
Two claims found in every argument
|
Inferential and Factual
|
|
Factual Claim
|
- a claim that evidence or reasons exist
-(premises which present genuine evidence) |
|
Inferential Claim
|
- a claim that the alleged evidence or reasons support something
|
|
Two types of Deductive Argu.
|
Valid or invalid
|
|
Valid Deductive Argu.
|
- impossible for conclusion to be false given that the premises are true
|
|
Invalid Deductuve Argu.
|
- deductive argu. in which it is possible for the conclusion to be false given that the premises are true
|
|
If te conclusion follows strictly from prems. the argument is ...
|
argument is valid
|
|
To test an argument for validity we begin by assuming ...
|
all the premises are true and try to find possible contradiciton in conclusion
|
|
Is validity determined by true statements?
|
No... validity is determined by the relationship between premises and conclusion
(ask the question do the prem. prove the conclusion ) |