Note: There is also a glossary at the end of your textbook. It is a good idea to look up terms you don't understand in both glossaries. I put mine together without reference to Prof. Hurley's, so our definitions will be stated differently. Sometimes having things explained two different ways is helpful. (His glossary also more extensive!)

Select the first letter of the word from the list above to jump to appropriate section of the glossary. If the term you are looking for starts with a digit or symbol, choose the '#' link.

A statement

a universal, affirmative categorical proposition.

accident

An informal fallacy of relevance in which a general
rule is misapplied in a case where an exception should obviously
be allowed.

ad hominem argument

An informal fallacy in which one
arguer uses a logically irrelevant "attack" on another
arguer as a reason to disregard the second arguer's argument. It
is a fallacy of relevance.
there are three types, Abusive, circumstantial and tu quoque.

affirmative proposition

A categorical proposition
which states that some or all of the subject
term is included in the predicate
term.

amphiboly

An informal fallacy of ambiguity in which
the arguer draws upon some ambiguity in the grammatical structure
of a statement to draw a false conclusion from it.

analogy

A comparison between two objects or events.

antecedent

The first part of a conditional
statement. If the antecedent is true the consequent will have to be true as well,
for the conditional statement to be true.

appeal to force

An informal fallacy in which a
threat is given as a reason to believe something, rather than a
premise.One of the fallacies of
relevance.

appeal to ignorance

An informal fallacy of weak induction,
in which the fact that we don't know whether something is or is
not the case is used as a reason to believe one way or the other.

appeal to pity

An informal fallacy in which pity
for the arguer is used as a reason to believe something rather
than a premise. A fallacy of
relevance

appeal to the people

An informal fallacy that uses the
listeners' desire as a reason to believe the conclusion, rather
than a premise. Can be direct or indirect.

appeal to
unqualified authority

An informal fallacy of weak induction
in which an authority is appealed to when there isn't good reason
to believe him/her.

**argument**An

**Argument**is a group of statements including one or more__premises__and one and only one__conclusion____.__The point of an argument is to give the receiver of the argument good reason to believe new information.

assumption

a premise that is implied, or is necessary
for the argument to be valid, but
is unstated.

begging the question

A group of informal fallacies of presumption, in
which the conclusion is actually assumed as a premise, though it
looks like new information is proven.

biconditional

symbolized with a tripplebar, a
biconditional is a statement that says two propositions are logically equivalent. An "if
and only if" statement.

categorical propositions

Statements that deal with inclusion or
exclusion of members of subject classes in predicate classes.

categorical syllogism

A deductive argument form made up of three categorical propositions.

causal inference

An inductive argument drawing conclusions about causes or
effects.

claim of inference

The claim of inference is an invisible but necessary part of
every argument. The arguer implies that there is a link between
the premises and the conclusion,
such that if the premises ore true, the conclusion will be true
as

cogent argument

A good inductive argument.
Since the premises are true and the form is strong,
there is good reason to believe the conclusion.

complex question

an informal fallacy of presumption in which
a question is asked that has another question embedded in it,
forcing the answerer to answer the embedded question as well.

complex proposition

A proposition or statement made out of two or more simple propositions. Also called a
compound proposition or compound statement.

composition

an informal fallacy of grammatical
analogy, in which a conclusion is
drawn about a * whole* (not a group-see hasty generalization) in the
basis of irrelevant characteristics of its parts.

compound proposition

see complex proposition

conclusion

**A conclusion** is a __statement__
in an __argument__ that
indicates of what the arguer is trying to convince the
reader/listener.well.

conditional statement

An if...then statement. The consequent
is conditional upon the antecedent.

conjoint premises

Conjoint premises work together to prove the conclusion. If one were dropped the other
wouldn't support the conclusion on its own.

conjunction

A complex proposition in which
two propositions are asserted to both be true. An "and"
statement.

connective

Symbols used in propositional
logic. See: P language.

consequent

The consequent follows the "then" in a conditional statement. Its
realization is conditional upon the antecedent .

consistent

An argument is consistent if the premises are not contradictory.

contingent

dependent upon a particular state of events to be true.

contradictory

When two propositions have opposite
truth values.

contraposition

An operation to manipulate the content of a standard form categorical proposition
without changing the truth value. Preserves truth value when used
on A and O statements only. subject
and predicate terms are switched,
as for conversion, and term
compliments are substituted for both terms.

contrary

When two statements can't both be true. (they could both be
false)

conversion

An operation to manipulate the content of a standard form categorical proposition
without changing the truth value. Preserves truth value when used
on E and I
statements only. The subject and predicate terms are switched.

copula

The word which connects subject and predicate terms in a standard form categorical proposition. The
only legal ones are "are" and "are not."

counterexample method

A process developed to prove a deductive
argument is invalid. The form of the argument is abstracted
and different content is substituted in to give clearly true premises and a clearly false conclusion. Also called
substitution method

deductive argument

An argument in which the premises are
intended to provide necessary support for the conclusion. Deductive arguments are either
valid or invalid.

disjunct

Both halves of a disjunction are
called disjuncts.

disjunction

An "either/or" statement.

disjunctive syllogism

A deductive argument in which one of the disjuncts of a
disjunctive statement, or disjunction, are denied, proving that
the remaining one must be true.

distribution

A term in a categorical proposition is
distributed if you know something about every member of its
class.

division

an informal fallacy of grammatical
analogy in which a conclusion is
drawn about a part of a whole on the basis of irrelevant
characteristics of the whole. In a sense, the opposite of composition.

dot

" · " The logical operator that stands for
"and." It is the main operator
of a conjunction.

E statement

A universal, negative, standard form categorical proposition.

enthymeme

a syllogism in which at least one of the
three propositions is unstated.

equivocation

An informal fallacy of ambiguity
in which a false conclusion is drawn on
the basis of a synonym.

existential fallacy

A formal fallacy in which an inference about a particular statement is drawn on
the basis of universal premises,
or, from the Aristotelian standpoint, when an inference is made
about things that do not exist.

extended argument

An extended argument is made up of more than one smaller
sub-arguments, in which the premises of the main argument are
themselves proven.

explanandum

the part of an explanation that is being explained. This is the
common knowledge.

explanans

The part of an explanation that gives new information. The
conjectured reasons for the explanandum.

explanation

Explains __why__ something is the case. An
explanation is sometimes difficult to distinguish from an argument
because it also involves reasons (and even "premise"
indicator words) But, unlike an argument, where the conclusion is
the "new" information, in an explanation, the statement
being explained--the **explanandum, **the part of the passage
that looks like a conclusion. --is usually a commonly accepted
fact. The ** explanans**, which can look like premises,
are the "new" information in an explanation, whereas
they are the accepted fact in an argument.

factual claim

One of the implied parts of every argument. the speaker implies
that the premises are true. (without this
claim they wouldn't be premises, only loosely associated
statements.)

fallacy of ambiguity

A group of informal fallacies in
which the inferential link
is faulty because of some ambiguity in the language of the argument.

fallacy of
grammatical analogy

A group of informal fallacies in
which the inferential link
is faulty even though they are grammatically analogous
to other good arguments.

fallacy of presumption

a group of informal fallacies in
which the information in the conclusion
of an argument is actually assumed in the
premises, thus not actually proving
anything new.

fallacy of relevance

a group of informal fallacies
pertaining to the inferential
relationship in arguments.
The premises are in some way logically irrelevant to the
conclusion, though they may have psychological or emotional
relevance.

fallacy of weak induction

a group of informal fallacies pertaining to the inferential relationship in inductive arguments. The premises
are irrelevant to the conclusion, but this fact is obscured in
some way.

false cause fallacy

An informal fallacy of weak inductuion
in which the arguer tries to claim a causal relationship about
two events that are most likely just coincidental.

false dichotomy

An informal fallacy of presumption based on a disjunction when there are actually more
than two choices.

figure

The figure of a categorical
syllogism refers to the arrangement of the middle terms in the premises.
The shirt collar mneumonic device can be used to remember the
four possible figures. They are used in conjunction with the mood to classify valid
and invalid categorical
syllogisms.

form of argument

the structure of the argument without any
of the contingent content. Usually, to
see the form, symbols or capital letters are substituted instead
of categories or simple
propositions.

formal fallacy

An invalid argument
in which the problem has to do with the form of the argument.

formal logic

The study of the the form of
arguments, unobscured by contingent
content.

generalization

an argument in which a conclusion is drawn about a group on the
basis of characteristics of a sample of the group.

hasty generalization

An informal fallacy of weak induction
in which a generalization is drawn
on the basis of a faulty sample.

horizontal pattern
argument

an extended argument in which the main pattern is of many
premises supporting one conclusion. Also called scattergun
argument.

horseshoe

" É" The logical operator
that is used to symbolize conditional
statements.

hypothetical syllogism

A deductive argument form made
out of three "linked" conditional
statements. (see also: syllogism)

- (empty)

I statement

A particular, affirmative, standard form categorical proposition.

indicator words

"red flags" in an argument that signal how its
components are to be interpreted. They may indicate premises, conclusions,
or type of argument. (deductive or
inductive)

inductive argument

An argument in which the premises are intended to provide
probable support for the conclusion. It is conceivable, in an
inductive argument, that the premises are all true but the
conclusion is false, this is just unlikely. (The sun will come up
in the east tomorrow morning, because it always has in the past
is an inductive argument)

inference

A jump of reasoning from known information to new information.
(See inferential relationship)

inferential claim

see: claim of inference

inferential relationship

The relationship between the premises and conclusion in a good
argument. See modus ponens.

informal fallacy

A bad (invalid or unsound) argument, where the problem has to do
with the contingent content of the
argument, and can't be detected by looking at the form itself.

invalid argument

A deductive argument which has
something wrong with the form. It is possible for the argument to
have true premises and a false conclusion. This is a bad argument, even
if the premises are true.

- (empty)

logic

the study of arguments.

logical equivalence

When two propositions have the same truth value. (It *does not*
mean that their contingent content has
the same meaning)

logical operators

Also called connectives, used in propositional logic. They are
the tilde, dot, wedge horseshoe and tripplebar.

main operator

The logical operator in a complex proposition that is
outside all parentheses.

major premise

The first premise in a standard form
categorical syllogism. It
contains the middle term and the major term.

major term

The term in a standard form caregorical syllogism which is
in the major premise and is the predicate term of the conclusion. Symbolized P.

middle term

The term in a standard form categorical syllogism which is
in the premises but not in the conclusion. Symbolized M.

minor premise

The second premise in a standard form
categorical syllogism. It
contains the middle term and the minor term.

minor term

The term in a standard form caregorical syllogism which is
in the minor premise and is the subject
term of the conclusion. Symbolized
S.

missing the point

an informal fallacy of relevance in which
the arguer gives premises that would support one conclusion, but
substitutes a different, usually extreme one instead.

modern (or
Boolean) square of opposition

A square of opposition in
which no assumptions are made about the
existence of the terms.

mood

The mood of a standard form categorical syllogism is a list
of the types of its three component propositions,
beginning with the major premise.

necessity

Something is necessary if it is impossible to imagine it not
being the case, even in a different possible world. Not
contingent upon any particular state of events or set of truth
values.

negative proposition

A categorical proposition
which states that some or all of the subject
term are excluded from the predicate
term.

O statement

A particular, negative, standard form categorical proposition.

obversion

An operation to manipulate the content of a standard form categorical proposition
without changing the truth value. The quality
of the proposition is changed without changing the quantity, and the term
compliment is substituted for the predicate
term. Preserves the truth value of all four types of
propositions.

P language

A language in symbolic logic
utilizing 5 logical operators, or connectives,
capital letters to stand for simple
propositions, and parentheses,
brackets and braces for punctuation. Sentences of this language
are called well formed
formulas or WFF's.

parentheses

"( )" used to enclose propositions in the language P,
keeping the meaning of the statement clear.

particular statement

When pertaining to a categorical
proposition, it is a statement that pertains to at least one
of the subject class.

practical logic

Often called critical thinking, it is the study of verbal
arguments, instead of focussing on the form as formal
logic does.

predicate term

The second term in a categorical proposition. It
is a * class* into which the subject term is included or from which
it is excluded. (ofter shortened to P term)

premise

A** Premise **is a __statement__
in an __argument__
that provides reason or support for the conclusion. There can be __one__
or __many__ premises in a single argument.

proposition

A statement. Propositions are sentences
or phrases that can be judged to be true or false, for example
"The sky is blue" and not "please hurry!"

propositional logic

The formal, symbolic
logic using the language P.

quality

When referring to standard form propositions the quality is determined by
whether the subject class * is*
(affirmative) or

quantifier

in categorical logic, the quantifier determines how much of the subject term is referred to by the predicate term. Standard form
quantifiers are all, some and no.

quantity

When referring to standard form propositions the quantity is determined
by the quantifier. It is either
uuniversal or particular.

red herring

an informal fallacy of relevance in which
the arguer leads listener astray with irrelevant statements
rather than premises.

reducing the scope

when working with term compliments, narrows down the range of
objects referred to.

self-contradictory
statement

A complex proposition that is
always false due to its structure. The opposite of a tautology.

simple proposition

the smallest possible proposition. If
it were cut into smaller parts it would no longer be a
proposition.

slippery slope

An informal fallacy of
weak induction in which the arguer gives a series of causal inferences that probably
won't come about.

sound argument

A "good" deductive argument. Since the conclusion
actually follows from the premises, and
the premises are true, the conclusion should be believed.

square of opposition

A standardized arrangement of standard
form categorical
propositions that portrays the relationships between the
types of propositions and aids in drawing inferences
on the basis of their properties.

standard form

English sentences are translated, following strict formal
guidelines, which make it possible to study arguments
objectively.

statement

A** statement** is a sentence that is either true or false,
such as "The cat is on the mat." Many sentences are not
statements, such as "Close the door, please" ,
"How old are you?"

strawman fallacy

An informal fallacy of relevance in which an
arguer presents a "straw" version of another arguer's
argument, defeats it, and pretends to have defeated the real
argument.

strong argument

An inductive argument with a good form.
The inferential relationship
is such that the premises provide probable
support for the conclusion.

subject term

The first term in a categorical proposition.
(the term which is being talked about). It must be a class, not a
singular term. (Often shortened to S term)

sub-alternation

The relation between propositions by
which it is inferred from a true universal
statement that the corresponding particular statement is true;
and from a false particular that the corresponding universal is
false.

sub-contrary

When two propositions can't both be
false, though they could both be true.

suppressed evidence

an informal fallacy of presumption that
obscures the existence of much stronger evidence that would
undermine the argument.

syllogism

A formal argument with two premises and one conclusion.

symbolic logic

A type of formal logic in which
symbols are used to study the properties of the form of the
argument.The most elementary symbolic language is P

tautology

A complex proposition that is
always true, because of the form of the statement.

term

A term is a simple component of a statement,
with a limited and definite meaning. In a categorical proposition the
term must signify a class.

term compliment

A term compliment is the opposite of a term.
Sometimes formed by adding "non-" to the term,
sometimes formed using prefixes, with longer terms you must reduce the scope of the term.

traditional square
of opposition

The square of opposition
developed by Aristotle which supports the maximum number of inferences. Only used when you can certify
that the terms involved exist.

tripplebar

" º " The logical operator that stands for
"if and only if." It shows that two propositions are logically equivalent. It
is the main operator in a bi-conditional statement.

truth function

The set of possible truth values a formal
complex proposition could
have, depending on the truth of the contingent content that could
be substituted into it. There is a four line truth table for each connective.

truth table

A truth table is a conventionalized arrangement of all the
possible combinations of truth values for the components of a
proposition or argument.

tilde

"~" The logical operator
that stands for "not." It is the main operator of a negation.

universal proposition

a standard form categorical
proposition with universal quanitfier.

valid argument.

A deductive argument in which
the premises provide necessary
support for the conclusion. It is
impossible for the premises to be true and the conclusion false.

venn diagram

A standardized drawing to help visualize categorical propositions and
categorical syllogisms. They
are created with overlapping circles to symbolize the different terms.

vertical pattern
argument.

An extendended argument in which
the main pattern is one of linked sub-arguments in a chain, one
conclusion being premise in the next argument.

weak analogy

An informal fallacy of weak induction
in which a poor analogy is drawn.

weak argument

An inductive argument with a
poor form. Even if the premises are true they wouldn't provide much
support for the conclusion.

wedge

"v" the logical operator
that stands for "or". It is the main operator in a disjunction.

well formed formula (WFF)

A readable sentence of the language P.
It is properly punctuated and unambiguous.

- (empty)
- Xeno. see Zeno

- (empty)

- (empty)

- (empty)

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