Logic and Critical Thinking
PHIL 1011
Logic and Meaning
Group Assignment
Name ID no.
1. Getabalew Manegerew UGR/6981/15
2. Girma Enkuchila UGR/8130/15
3. Mesfin TiKi UGR/4048/15
4. Dawit UGR/15
5. Deballera UGR
Submitted to:
May, 2023 G.C
Addis Ababa, Ethiopia
Table content
Topics. Page
Logic and meaning. 1
Intension and Extension of Terms. 2
Definition and Purpose. 3
Techniques of Definition. 4
Lexical Rule. 5
Logic and meaning
Philosophy of language is the reasoned inquiry into the origins of language, nature of meaning, the
usage and cognition of language and the relationship between language and reality. It is an
important discipline in its own right and hence, it poses questions like "what is meaning?"," how
does language refer to the world? “and etc.
Language is a body of standard meanings of words and the form of speech used as a means of
expressing the feeling, emotion, desire, thought etc. in a consistent pattern of communication.
Philosopher Ludwig Wittgenstein thought that the number of functions of language to be virtually
unlimited. Language can be used in every aspects of everyday life. i.e.
-To form hypothesis – Give command
- Argue with others - Tell jokes
For our purpose, two linguistic functions of language are particularly important:(i) to convey
information ( ii) to express feelings
• Terminology that conveys information is said to have cognitive meaning.
• Terminology that expresses feeling is said to have emotive meaning.
Logic is concerned chiefly with cognitive meaning. While, emotive meanings encompasses value
claim. Value claim is that something is good, bad right, wrong,better,worse, more important, less
important than some other thing. For purpose of logic, we must be able to disengage the value
claims of emotively charged statements. In arguments, emotive terminology accomplishes basically
the same function as it does in statements.
Definition
If we consider cognitive meaning specifically from emotive meaning, two defectives may raise.
Namely they are vagueness and ambiguity.
A vague expression: is one that allows for borderline cases in which it is impossible to tell if the
expression applies or does not apply. Trouble arises only when the language is not sufficiently
precise for what the situation demands.
An ambiguous expression: is one that can be interpreted as having more than one clearly distinct
meaning in given context. It can affect entire statement. Such ambiguity and vagueness is that vague
terminology allows for a relatively continuous range of interpretations. A vague
Due to those blurred and mixed up expressions a conflict may occurred. The role of vagueness and
ambiguity in arguments may be conveniently explored in the context of conflicting arguments
between individuals. Such conflicts are called disputes.
Disputes are generally classified into two. Namely
Verbal disputes : are disputes from vagueness or ambiguity of words.
Factual dispute : are disputes from given fact.
The Intension and Extension of Terms
A term is any word or arrangement of words that may serve as the subject of the statement. Terms
consists of proper names, common names and descriptive phrases.
Here are some examples;
- Proper names: Napoleon, North Dakota etc.
- Common names: Animal, restitution, activity... etc.
- Descriptive phrases: President of CBE, Captain of St. George... etc.
Words that are not terms include verbs, non-substantive adjectives, adverbs, propositions,
conjunctions, and all non-syntactic arrangements of words. It is important to distinguish the use of
word from the mention of a word, without this distinction any word can be imagined to serve as the
subject of a statement and, therefore count as a term. Words are unusually considered to be
symbols and the entities they symbolized are usually called meaning. Terms being made of words,
are also symbols, but the meaning they symbolize are of two kinds.
The Intensional meaning: consists of the qualities or attributes the term connotes.
The Extensional meaning: consists of the members of the class that the term denotes.
For instance, the intension of the tern “ cat “ consists of the attributes of being furry, of having four
legs, of moving in a certain way, of emitting certain sounds and so on. And the extension consists if
the cats themselves, all the cats in the universe.
Intention and Extension are roughly equivalent to the modern terms “sense” and “reference”
respectively. Because of subjective elements inevitably lead to confusion when it comes to
identifying the connotation of specific terms, logicians typically restrict the meaning of connotation
to what may be called conventional connotation. The conventional connotation of a term consists of
the properties or attributes that the term remains more or less the same from person to person and
from time to time. The denotation of a term also typically remains the sane form person to person,
but it may change with passage of time. Sometimes the denotation of a term can change radically
with the passage of time. Accordingly, these terms at specific time have what is called empty
extension.
The intensional meaning of a term serve as the criterion for deciding what the extension consists of.
One kind of term that raises problems for the intension determine the extension rule is proper
names. For example, the name “John” might not appear to have any intension, but it denotes the
person who has this name. The possible solution for such like intensional meaning problems is
proper names consists of the casual chain of events leading from the point at which certain person
learns about the name.
A series of terms maybe either increasing or decreasing in meaning if it arranged in such order.
Increasing intension meaning is the same as decreasing extension. Increasing intension is connoting
more attribute than the previous, while decreasing extension the opposite one. Example: animal,
mammal, primate, homo.
Decreasing intensional meaning is to mean increasing extension. Each term in the series denotes a
class having more members than the preceding term. Example: homo, primate, mammal, animal.
Definition and Purpose
Definition means a group of words that assigns a meaning to some word or a groups of word.
It has two parts: Definiendum and Definies
Definiendum is a group of word that is supposed to be defined.
Definies is a group of words that does the defining.
For Example: “Bachelor" is defined as Unmarried man.
The word "Bachelor" is definiendum and Unmarried man is Definies.
Based on function (usage) they have definition is classified in to five
1.Stipulative definition
Assigns a meaning to word for first time
Its assignment is arbitrary (random) and has no truth value(true or false
Caused by new phenomena and development
It used to simplify complex expression
It used to set new secret code.
For Example: "operation sunset"Ethio _Eritrea war in (1998).
2.laxical Definition (reportive Definition)
It report the meaning of words actually exist in dictionary.
It provides dictionary meaning of terms
It has truth value
It is important to avoid ambiguity by listing various meaning of word that have.
For example: “Prime number" Number divisible by 1 and itself.
3.precising Definition
It make a vague term more precise, often for specific purpose.
Reduce blurredness of words
A word used in systematic context such as science, medicine, Mathematics, law are.
Precising Definition
For example,: “Antique" means at least 100 years old
4.Theorical Definition
Assigns a meaning to word by suggesting theory that gives a certain characterization
It has no truth value
Help in general understanding and scientific practice
For example: “light” is form electromagnetic radiation
5.Persuasive Definition
Endanger favorable or unfavourable attitude toward what is denoted by Definiendum
It used to win acceptance of audience
It used to change attitude of audience
To persuade listeners
To stir emotion
For Example:"Federalism"is s political intrigue that provides legitimate ground For
emergence of new regional warlord's..
Techniques Of Definition
Extensional (Denotati ve) Defi niti onal Techniques.
Extensional Definition- assign meaning to a term by indicating a member.
There are many ways of indicating extensional meaning of a term.
1.Demonstrative(ostensive) Definition-It uses pointing as a technique to define terms
Example-"Chair" means 👉This 👉this and 👉this by pointing.
2.Enumerative Definition-assign meaning by naming partial or complete member of class.
Example-"Actor" means a person such as Mahder Asefa, Samson Taddese...
3.Definition by sub class -Assign a meaning to a term by naming subclass of class.
Example- "Fiction" means poem, a novel, short story...
Intentional (connotative) Definitional Technique
The intentional Definition-assign meaning by indicating the quality or attributes of term.
1.Synonymous Definition -define with other similar word.
Example-"Observe" means see.
2.Etymological meaning-assign meaning by disclosing the word ancestry.
Example-"License" means derived from Latin word which means permitted.
3.Operational Definition-assign a meaning by specifying certain experimental procedure.
Example- a solution is an "acid” if and only if litmus paper turned red when dipped into it.
4.Definition by genus and difference -assign a meaning by identifying species genus and
difference.
Example- "Ice “means Species Difference Genus
Ice frozen water
It is the most effective way from all intentional definition.
Criteria for lexical definition
It is appropriate that we have a set of rule to construct our own lexical definition and to evaluate
others. Those rules specifically intended for lexical definition.
Rule 1: A lexical definition should conform to the standards of proper grammar.
- A definition like any other form of expression, should be grammatically correct.
Rule 2: A lexical definition should convey the essential meaning of the word being defined.
- If we defined the word ‘’stone” as type of substance it says nothing about the
“stone” specific features rather the word “stone” defined as ; hard solid non
metallic minerals matter of which stone is made .
Rule 3: A lexical definition should be neither too broad nor too narrow.
- If a definition is too broad, the definiens include too much if it is too narrow, the
definiens includes too little. Only synonymous definition and definition by genus
and difference prone to this deficiency.
Rule 4: A lexical definition should not be circular
- Sometimes circularity appears with pairs of definitions. However, sometimes
definition maybe intrinsically circular.
- Example: “ silence “ means the state of being silent
Rule 5: A lexical definition should not be negative when it can be affirmative.
- To be definitions paulisable, the definition should be affirmative as possible
Example: “ Equilibrium “ is absence of unbalanced forces. ( less paulisable )
“ Equilibrium “ is a state of balanced influence. ( more paulisable )
Rule 6: A lexical definition should not be, expressed in figurative, obscure, vague, or ambiguous
language
- A definition is figurative if it involves metaphors or intended to paint a picture
instead of exposing the essential meaning of a term
- A definition is obscure if its meaning is hidden as a result of defective or
inappropriate language
- A definition is vague if it lacks precision or if its meaning is blurred that is, if
there is no way of telling exactly what class of things the definition refers to.
- A definition is ambiguous if it lends it self to more than one distinct
interpretation.
Rule 7: A lexical definition should avoid affective terminology
- Affective terminology is any kind of word usage that plays upon emotions of the
reader or listener.
Rule 8: A lexical definition should indicate the context to which the context of the definiens pertains.
- This rule applies to any definition in which the context of the definiens is
important to the meaning of the definiendum.
