Categorical Logic I
Contradictories Validity for Arguments Containing Categorical Propositions Immediate Inferences The Theory of the Syllogism
Contradictories
Contradictories are two propositions that cannot be true simultaneously. When people say
Logic is the science argumentation
Includes systems of methods and principles that we can use as a criteria for
evaluating the arguments of others as well as to guide the construction of our
arguments
Arguments
consist of a group of one or more support
Fallacies of Presumption
assume that which needs to be proven
Begging the Question
arguer creates the illusion that inadequate premises provide
adequate support for the conclusion
you assume that the conclusion is true in your premises, or you
leave
Fallacies of Weak Induction
Appeal to Ignorance
occurs when the premises of an argument state that nothing has been proved
one way or the other about something, and the conclusion then makes a definite
assertion about that thing
No one has proved the mo
Fallacy refers to a kind of reasoning failure involving invalid reasoning or
otherwise faulty argumentation
generally the products of either a mistake in reasoning or the intentional creation
of an illusion
formal fallacies illicit moves in deductive a
Fictional terms have an empty extension, some non-fictional have empty extensions too
Definiendum word or group of words that is supposed to be defined (word:
cat)
Definiens word/group of words that does the defining (definition: small,
domesticated.etc)
Argument Forms & Extended Structures
form of the argument determines whether or not that argument is valid
arrangement of letters such that consistent substitution of words or phrases for each
letter results in an arguments
P1: All A are B
P2: All C are
Ordinary language serves a wide variety of functions
conveying information
expressing and evoking feelings
Cognitive Meaning
terminology that conveys factual information has a cognitive
meaning
Emotive Meaning
terminology that expresses or evokes f
Rules of Implication
Natural deduction is a method for deriving the conclusion of valid arguments
expressed in the symbolism of propositional logic
The method consists of using sets of Rules of Inference (valid argument forms)
to derive either a conclu
Propositional Logic
studies the relationships and properties that come out of methods for combining
or altering statements
does not look inside the statements
blind to content
simplest statements are treated as indivisible units
simple statements:
Rhetoric and Evaluation
Types of Rhetoric- indirect statements/questions Rhetorical questions
1/22/2008 2:05:00 PM
o "Are you deaf?" Really means I said something and you did not hear it or are ignoring it. Please respond. How can we infer this
Language and Logic part 2
Propositional Conjunctions &, = "and" p q = p and q = or = not p = not p it is not the case that p. Cojunctions Chomsky is smart Haufe is a fool
2/21/2008 2:04:00 PM
o Chomsky is smart and Haufe is a fool What are the poss
Categorical Logic I
Beyond Propositional Logic Categorical Propositions The Four Basic Categorical Forms
What Are Categories?
categories are supposed to reflect reality - real divisions in nature. Language is entirely reliant on categories as tools
PHIL 1503
1. _J_ J J _p_ p p
XXIII Answer Key p T F pq T T T F pp T F q T F T F p F . F . T . T .
p T F p T T F F q T F T F
VALID 2. N A A_ N pq q_ p
INVALID 3. (I I) D D VALID (p p) q q
p T T F F
q T F T F
(p p) q TF T TF F TT T TT F
Types of Arguments
Mathematical Arguments provide deductive arguments for
mathematical statements
Inductive Arguments have conclusions that go beyond the
information that is contained in hte premises
premises give reason to accept the conclusion but n