Combining Texts

All the ideas for 'Prior Analytics', 'First-order Logic, 2nd-order, Completeness' and 'On Mental Entities'

expand these ideas     |    start again     |     specify just one area for these texts


27 ideas

4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
Aristotle was the first to use schematic letters in logic [Aristotle, by Potter]
Aristotelian syllogisms are three-part, subject-predicate, existentially committed, with laws of thought [Aristotle, by Hanna]
Aristotelian sentences are made up by one of four 'formative' connectors [Aristotle, by Engelbretsen]
Aristotelian identified 256 possible syllogisms, saying that 19 are valid [Aristotle, by Devlin]
Aristotle replaced Plato's noun-verb form with unions of pairs of terms by one of four 'copulae' [Aristotle, by Engelbretsen/Sayward]
Aristotle listed nineteen valid syllogisms (though a few of them were wrong) [Aristotle, by Devlin]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
Aristotle's said some Fs are G or some Fs are not G, forgetting that there might be no Fs [Bostock on Aristotle]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
There are three different deductions for actual terms, necessary terms and possible terms [Aristotle]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg]
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
There are at least seven possible systems of semantics for second-order logic [Rossberg]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence is intuitively semantic, and captured by model theory [Rossberg]
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
Deduction is when we suppose one thing, and another necessarily follows [Aristotle]
Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Aristotle places terms at opposite ends, joined by a quantified copula [Aristotle, by Sommers]
In proof-theory, logical form is shown by the logical constants [Rossberg]
5. Theory of Logic / E. Structures of Logic / 7. Predicates in Logic
Aristotle's logic is based on the subject/predicate distinction, which leads him to substances and properties [Aristotle, by Benardete,JA]
5. Theory of Logic / G. Quantification / 1. Quantification
Affirming/denying sentences are universal, particular, or indeterminate [Aristotle]
5. Theory of Logic / G. Quantification / 3. Objectual Quantification
Aristotelian logic has two quantifiers of the subject ('all' and 'some') [Aristotle, by Devlin]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness can always be achieved by cunning model-design [Rossberg]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
A deductive system is only incomplete with respect to a formal semantics [Rossberg]
10. Modality / A. Necessity / 4. De re / De dicto modality
A deduction is necessary if the major (but not the minor) premise is also necessary [Aristotle]
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
Sense-data are dubious abstractions, with none of the plausibility of tables [Quine]
12. Knowledge Sources / D. Empiricism / 4. Pro-Empiricism
Empiricism says evidence rests on the senses, but that insight is derived from science [Quine]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Linguistic terms form a hierarchy, with higher terms predicable of increasing numbers of things [Aristotle, by Engelbretsen]