21 terms

# logic flashcards set 3

chapters 10-13
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Reasoning
the act by which the mind requires new knowledge by means of what it already knows
the two kinds of reasoning
deductive and inductive
Deductive inference
the act by which the mind establishes a connection between the antecedent and the consequent.
Syllogism
a group of propositions in orderly sequence, one of which (the consequent) is said to be necessarily inferred from the others (the antecedent).
Essential Law of Argumentation
If the antecedent is true, the consequent must also be true.
First Corollary
If the syllogism is valid and the consequent is false, then the antecedent must be false.
Second Corollary
In a valid syllogism with a true consequent, the antecedent is not necessarily true.
Syllogism Terms
major, minor, middle
Major Term
the predicate of the conclusion
Minor Term
The subject of the conclusion
Middle Term
The term that appears in both premises, but not in the conclusion
Major Premise
The premise which contains the major term
Minor Premise
The premise which contains the minor term
The Principle of Reciprocal Identity
Two terms that are identical with a third term are identical to each other.
The Principle of Reciprocal Non-Identity
Two terms, one of which is identical with a third term and the other of which is nonidentical with that third term, are nonidentical to each other.
The Dictum de Omni
What is affirmed universally of a certain term is affirmed of every term that comes under that term
The Dictum de Nullo
What is denied universally of a certain term is denied of every term that comes under that term.
The 3 catagories of the 7 rules of catagorical syllogisms
Terminological, Quantitative, Qualitative
Terminological Rules
I. Ther must be three and only three terms. II.The middle term must not occur in the conclusion
Quantitative Rules
III. If a term is distributed in the conclusion, then it must be distributed in the premise. IV. The middle term must be distributed at least once.
Qualitative Rules
V. No conclusion can follow from two negative premises. VI. I the two premises are affirmative, the conclusion must also be affirmative. VII. If either premise is negative, the conculsion must be negative.