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Introduction
Offline video lecture announcement due to a scheduling conflict.
Instructor wishes students a happy and successful new year.
Recap of Previous Content
Last topic covered in December: different theories of meaning.
Three basic approaches:
Cognitive Semantics (Ideas Approach):
Meanings are considered as representations in the mind.
Usage Theory of Meaning:
Meaning of a word is determined by its usage in context, highlights distributional semantics.
Truth Conditional Semantics:
Focus on modeling aspects of meaning that determine the truth conditions of sentences.
Detailed Overview of Truth Conditional Semantics
Truth conditional semantics takes a neutral stance regarding the true nature of meanings.
Focus is on evaluating if a sentence can be assessed as true or false based on the speaker's knowledge.
Philosophical implications:
The nature of truth is a long-standing question in philosophy, with no consensus.
Truth is conceptualized as a correspondence between a sentence and a factual state in the world.
Theories of Truth
Correspondence Theory of Truth:
Truth is when a statement corresponds to actual facts or states of affairs.
Example: "It is raining today" is true if it is indeed raining.
Challenges to the correspondence theory include:
Applicability to mathematical truths, e.g., the sum of angles in a triangle.
Reality of abstract concepts like numbers—do they exist concretely?
Platonism and Realism:
Philosophical stance asserting the existence of an abstract realm of mathematics.
Coherence Theory of Truth:
Truth is defined by the consistency of beliefs within a given theoretical framework.
Pragmatic Theory of Truth:
Truth is based on the practical benefits or usefulness of ideas in real-world scenarios.
Constructivist Theory of Truth:
Truth is seen as a negotiated outcome within social discourse without objective standards.
Relationship Between Meaning and Truth in Truth Conditional Semantics
Truth conditional semantics uses the correspondence theory of truth for evaluation.
Introduces the concept of possible worlds—alternative scenarios to evaluate sentences.
A sentence could be true in one possible world but false in another, influenced by the context (e.g., literary narratives).
Reference: meaning establishes a relationship between language and aspects of the world.
Reference in Semantics
Reference:
Broader than truth; it includes the relationship between language and the entities it describes.
Identified through proper names, definite descriptions, and common nouns.
Frega's Insights on Reference:
Example of the morning star vs. evening star: two names for the same object (Venus) that lead to different implications about knowledge and meaning.
Extension and Intension:
Extension: the actual object or set that an expression refers to.
Intension: the cognitive information needed to identify the reference.
Compositionality Principle
The meaning of complex expressions derives from their constituents and how they are combined (Frega's principle of compositionality).
Examples include:
Simple sentences: subject and predicate performance.
Locality in semantic computation: only immediate parts of a complex expression contribute to its overall meaning.
Semantic Structures and Sentence Extensions
The extension of sentences equates to their truth value (true or false).
In declarative sentences:
True sentence extensions yield a value of 1.
False sentence extensions yield a value of 0.
Distinguishes between meaning (which varies) and truth value (which remains binary).
Summary of Key Points
Truth conditional semantics focuses on aspects of meaning relevant to establishing truth conditions.
The distinction between reference and meaning is crucial for understanding semantics.
Compositionality encompasses both syntactic and semantic approaches, where meanings are computed recursively through structures.
Extensions correspond to real-world references or truth values, while intentions capture the information needed to understand these references.