Philosophy of Language & Logic

Reference theory of meaning

The meaning of a word is what the word refers to.

Compositionality

The meaning of a complex expression comes from the meanings of its smaller expressions and combination rules.

Problem solved by compositionality

Explains how we can understand sentences that we have never heard before using a limited vocabulary.

Word meaning and propositions

Word meanings contribute to the whole sentence; changing a word can change the proposition and truth value.

Idea theory of meaning

The meaning of a word is the idea or mental image associated with that word.

Meaning as use

A word gets its meaning from how it is used in sentences rather than independently.

Sense and reference

Sense is the way we understand something, while reference is the actual thing the word refers to.

Three purposes of definitions

Reportive (how people use it), Stipulative (assigns a new meaning), and Essentialist (essential characteristics).

Stipulative definition

Gives a word a meaning by simply declaring what the word will mean.

Essentialist definition

Tries to explain what something really is by looking at its underlying nature.

Genus-species definition

Starts with a broad category and gives the characteristic that distinguishes it from other members.

Ostensive definition

Explains a word by showing an example of what it refers to.

Synonym method

Defines a word by giving another word that means approximately the same thing.

Operational method

Defines a word by giving a test, measurement, or procedure for determining if it applies.

Contextual method

Explains a word by placing it in a sentence or situation where its meaning becomes clear.

Necessary condition

Something that must be true for something else to be true.

Sufficient condition

Something that is enough to guarantee something else is true.

Example of necessary and sufficient conditions

A shape having four equal sides and four right angles for being a square.

Definition that is too broad

Includes things that should not be included in the word's meaning.

Definition that is too narrow

Leaves out things that should be included in the word's actual meaning.

Circular definition

Uses the word being defined, either directly or indirectly, to explain itself.

Obscure definition

Uses unclear, vague, or overly metaphorical language, failing to clearly explain the term.

False definition

Gives an incorrect description of what something is.

Principle of charity

Interpret someone's argument in the most reasonable and defensible way possible.

Ambiguity

Occurs when a sentence or word can have more than one distinct meaning.

Equivocation

Happens when someone uses the same word in two different meanings within an argument.

Vagueness

Occurs when a word or sentence does not have a precise boundary for when it applies.

Ambiguity vs. vagueness

Ambiguity means multiple distinct meanings; vagueness means lacking a precise boundary.

Use vs. mention

Use talks about the thing a word refers to; mention talks about the word itself.

A priori knowledge

Knowledge justified through reasoning or thinking alone, without experience.

A posteriori knowledge

Knowledge that depends on observation, experience, or scientific investigation.

Necessary truth

A proposition that is true in every possible world.

Contingent truth

True in some possible worlds but false in others.

Analytic sentence

True because of the meanings of the words that make it up.

Contradictory sentence

False because of the meanings of the words that make it up.

Synthetic sentence

Truth depends on facts beyond the meanings of its words.

Empiricism's problem with mathematics

Mathematical knowledge does not seem to come from observation.

Logical empiricists' response

Argued that mathematical truths are analytic and true based on the meanings of words.

Truth vs. knowledge

Something can be true without us knowing it; the limits of knowledge do not determine truth.

Verificationism

The idea that meaningful empirical claims must be capable of being verified through observation.

Quick Formula: Reference theory

Meaning → what it refers to

Quick Formula: Idea theory

Meaning → mental idea

Quick Formula: Meaning as use

Meaning → how it's used

Quick Formula: Compositionality

Word meanings + combination rules → sentence meaning

Quick Formula: Reportive definition

How people use it

Quick Formula: Stipulative definition

We assign the meaning

Quick Formula: Essentialist definition

What it really is

Quick Formula: Necessary condition

Must have

Quick Formula: Sufficient condition

Enough to prove

Quick Formula: Ambiguous

Multiple meanings

Quick Formula: Vague

Unclear boundary

Quick Formula: A priori

Reason

Quick Formula: A posteriori

Experience

Quick Formula: Necessary truth

True in every possible world

Quick Formula: Contingent truth

True in some possible worlds

Quick Formula: Analytic

True by meaning

Quick Formula: Contradictory

False by meaning

Quick Formula: Synthetic

Truth depends on facts