more on this theme     |     more from this thinker


Single Idea 10297

[filed under theme 5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems ]

Full Idea

The Löwenheim-Skolem theorem is usually taken as a sort of defect (often thought to be inevitable) of the first-order logic.

Gist of Idea

The Löwenheim-Skolem theorem seems to be a defect of first-order logic

Source

Stewart Shapiro (Higher-Order Logic [2001], 2.4)

Book Ref

'Blackwell Guide to Philosophical Logic', ed/tr. Goble,Lou [Blackwell 2001], p.49


A Reaction

[He is quoting Wang 1974 p.154]


The 12 ideas from 'Higher-Order Logic'

First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro]
Second-order variables also range over properties, sets, relations or functions [Shapiro]
Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro]
Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro]
The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
Some say that second-order logic is mathematics, not logic [Shapiro]
If the aim of logic is to codify inferences, second-order logic is useless [Shapiro]
Logical consequence can be defined in terms of the logical terminology [Shapiro]
The axiom of choice is controversial, but it could be replaced [Shapiro]