Logic in a Nutshell
The full definition of logic
"Logic is the art which enables us to proceed with order, ease, and correctness in the act of reason"
Healthy, spark, bushy, and bad are examples of what kind of signification?
What are Analogous Terms.
The First Law of Opposition states this.
Contradictories cannot both be true at the same time, nor can they both be false.
This fallacy occurs when the middle term is ambiguous: specifically, when it is used equivocally.
What is the Fallacy of Equivocation.
Syllogisms, the verbal expressions of deductive inference, are defined in this way.
What is "a group of propositions in orderly sequence, one of which (the consequent) is said to be necessarily derived from the others (antecedent)."
The major division of logic includes these two branches.
What is formal logic and material logic.
The process by which a simple apprehension is derived from sense perception and a mental image.
What is Abstraction.
What is "a statement which expresses truth or falsity."
The Fallacy of Illicit Process
What is "when either the major or minor terms appear distributed in the conclusion but not in the premises."
The major premise in a syllogism is constructed from these two terms.
What is "the predicate of the conclusion and the middle term."
An argument is valid when it fulfills these conditions.
The completely articulated sum of the intelligible aspects, or elements, or notes represented by a concept.
What is Comprehension.
Every proposition includes these four elements.
What are Quantifier, Subject-Term, Predicate-Term, and Copula.
"Cinderella is not going to the ball. Since no balls are fun, it's evident that Cinderella is not going to not have fun."
What is The Fallacy of Exclusive Premises
The principle of Dictum de Omni states that...
What is "what is universally affirmed of a term is also affirmed of every term that falls under its extension."
The verbal expressions of the three mental acts deal with in logic.
What is term, judgment, and syllogism.
This rule allows logicians to distinguish between comprehension and extension.
What is "The greater comprehension a concept has, the less extension it has; and the greater extension a concept has, the less comprehension it has."
When logicians say a term is distributed, they mean this.
What is "a term refers to the entire extension or all the members of the class of things referred to.
Whatever does not listen to reason, cannot be governed by reason.
Falling in love does not listen to reason.
Therefore falling in love cannot be governed by reason
What is the Fallacy of Illicit Major
The first corollary to the Essential Law of Argumentation states...
What is "if the syllogism is valid and the consequent is false, then the antecedent is also false."
"The correspondence of a statement to reality."
What is truth.
Terms that are pronounced exactly alike but have different and unrelated meanings.
What are "Equivocal Terms."
You can use the tool of contraposition two produce a logically equivalent form of these two kinds of propositions.
What are A and O statements.
Some books are sources of amusement.
All logic books are books.
Therefore some logic books are sources of amusement.
What is the Fallacy of Undistributed Middle
The Seven Rules for Valid Categorical Syllogism
What is:
1. There must be three and only three terms.
2. The middle term must not be used in the conclusion.
3. A term distributed in the conclusion must be distributed in the premises.
4. The middle term must be distributed at least once.
5. No conclusion can follow from two negative premises.
6. If both premises are affirmative, the conclusion must be affirmative.
7. If either premise is negative, the conclusion must be negative.