Terms - Exam #2 Flashcards
What are the three acts of the mind? (review)
1) Simple Apprehension
2) Judgement
3) Reasoning
Syllogism
the fundamental building block of categorical logic
Enthymeme
A syllogism with an omitted premise or conclusion
Validity
A valid argument is such that a true conclusion NECESSARILY follows from true premises.
Law of Non-Contradiction
A proposition and its negation cannot both be true. (Ex. “All cats are dogs” and “no cats are dogs”)
The Law of Identity
Everything in the universe is the same thing as itself. (Ex. x=x).
Law of Excluded Middle
There is no middle ground between truth and falsity; something is either true or false.
Consistency
If propositions are consistent, they can both be true at the same time.
Implication
When one statement implies another. If A is true, then B must be true.
Mood
The the arrangement of the claims in a standard form of syllogism (Ex. AAA, EAE, AII, EIO)
Major term
The predicate of the conclusion
Minor term
Subject of the conclusion
Middle term
The term that only appears in the premises
Major premise
Whichever premise the major term is in (the first premise in standard form).
Minor premise
Whichever premise the minor term is in (the second premise in standard form).
Figure 1 Syllogism
MP
SM
∴ SP
Figure 2 Syllogism
PM
SM
∴ SP
Figure 3 Syllogism
MP
MS
∴SP
Figure 4 Syllogism
MP
SM
∴SP
Figure of a Syllogism
Categorization of a syllogism based on the arrangement of the middle terms. Has impact on validity.
Distribution
Whether the term includes all which may be categorized under that term. (For example, “All [cats] are [mammals}” does not mean “All [mammals] are [cats]” because the term [mammals] is undistributed. It does not include all mammals.
Distribution of an A Claim
Subject distributed, predicate undistributed
Distribution of an E Claim
Subject distributed, predicate distributed
Distribution of an I Claim
Subject undistributed, predicate undistributed
Distribution of an O Claim
Subject undistriubted , predicate distributed
Rules of the Syllogism per Aristotle (assuming a standard form categorical syllogism)
1) Only three terms (Fallacy of Four Terms)
2) Only three propositions
3) Middle term must be distributed at least once (Fallacy of Undistributed Middle)
4) Any claim distributed in the premises must be distributed in the conclusion (Fallacy of Illicit Major/Minor)
5) No syllogism may have two negative premises (Fallacy of Two Negative Terms)
6) If one premise is negative, the conclusion must be negative; if the conclusion is negative, one premise must be negative (the number of negative conclusions must equal the number of negative premises).
Particular Corollaries to the Rules of Syllogisms
1) No syllogism may have two particular premises
2) If a syllogism has a particular premise, it must have a particular conclusion
EIO (Old Macdonald) Syllogism
Valid in all four figures.
Demonstrative Syllogism
A syllogism that proves the essence of something
How to construct a demonstrative syllogism
1) Work in reverse, starting with the conclusion
2) Seek the minor premise first - discover what the best possible middle term could be as relating to the minor term.
3) Always use a AAA Fig. 1 (Barbara) syllogism if possible.
Sorites
A chain of syllogisms stacked on top of each other
Epichirema
A sorites made up of enthymemes
