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Single Idea 13346

[filed under theme 5. Theory of Logic / A. Overview of Logic / 6. Classical Logic ]

Full Idea

The most fundamental notion in classical logic is that of truth.

Gist of Idea

Truth is the basic notion in classical logic

Source

David Bostock (Intermediate Logic [1997], 1.1)

Book Ref

Bostock,David: 'Intermediate Logic' [OUP 1997], p.3


A Reaction

The opening sentence of his book. Hence the first half of the book is about semantics, and only the second half deals with proof. Compare Idea 10282. The thought seems to be that you could leave out truth, but that makes logic pointless.

Related Idea

Idea 10282 Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W]


The 27 ideas with the same theme [system of logic accepted as the modern norm]:

Demonstrations by reductio assume excluded middle [Aristotle]
A language: primitive terms, then definition rules, then sentences, then axioms, and finally inference rules [Tarski]
Elementary logic requires truth-functions, quantifiers (and variables), identity, and also sets of variables [Quine]
In classical logic, logical truths are valid formulas; in higher-order logics they are purely logical [Dummett]
Deductive logic is the only logic there is [Harman]
Truth is the basic notion in classical logic [Bostock]
Elementary logic cannot distinguish clearly between the finite and the infinite [Bostock]
Fictional characters wreck elementary logic, as they have contradictions and no excluded middle [Bostock]
Classical logic is our preconditions for assessing empirical evidence [Kitcher]
I believe classical logic because I was taught it and use it, but it could be undermined [Kitcher]
Classical logic is bivalent, has excluded middle, and only quantifies over existent objects [Jacquette]
Indeterminacy is in conflict with classical logic [Fine,K]
Classical logic neglects the non-mathematical, such as temporality or modality [Burgess]
Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess]
The Cut Rule expresses the classical idea that entailment is transitive [Burgess]
In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares]
Material implication (and classical logic) considers nothing but truth values for implications [Mares]
The non-emptiness of the domain is characteristic of classical logic [Read]
Classical logic is good for mathematics and science, but less good for natural language [Sider]
Logical relativism appears if we allow more than one legitimate logical system [O'Grady]
Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher]
Doubt is thrown on classical logic by the way it so easily produces the liar paradox [Horsten]
The underestimated costs of giving up classical logic are found in mathematical reasoning [Halbach]
Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward]
The case for classical logic rests on its rules, much more than on the Principle of Bivalence [Rumfitt]
Classical logic rules cannot be proved, but various lines of attack can be repelled [Rumfitt]
If truth-tables specify the connectives, classical logic must rely on Bivalence [Rumfitt]