A valid deductive argument form where if a disjunction (P or Q) is true and one disjunct (P) is false,…
Dialetheism posits that some statements can be both true and false simultaneously. This radical view challenges classical logic's principle of…
A destructive dilemma is a logical argument form. It uses two conditional statements and negates their consequents to disprove at…
A definite description is a linguistic phrase that uniquely identifies a specific person, place, or thing. Often signaled by the…
The definiens refers to the words or phrases used to explain the meaning of a definiendum. It's the part of…
Two theories are deductively equivalent if they can prove the exact same set of theorems. This means they offer the…
Deductive consequence, also known as syntactic consequence, refers to the relationship where a conclusion logically follows from premises based solely…
Counterpart theory, proposed by David Lewis, offers a philosophical interpretation of modal logic. It posits that objects in one possible…
A conditional statement exploring hypothetical scenarios against a backdrop of necessary truths. It examines implications when the premise contradicts what…
Counterfactual logic explores conditional statements about what would have happened if something else had occurred. It's crucial for understanding causality,…