Combining Philosophers

All the ideas for Thrasymachus, C. Anthony Anderson and Fred Sommers

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20 ideas

3. Truth / B. Truthmakers / 5. What Makes Truths / a. What makes truths
Truthmakers are facts 'of' a domain, not something 'in' the domain [Sommers]
4. Formal Logic / A. Syllogistic Logic / 3. Term Logic
'Predicable' terms come in charged pairs, with one the negation of the other [Sommers, by Engelbretsen]
Logic which maps ordinary reasoning must be transparent, and free of variables [Sommers]
4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
Free logics has terms that do not designate real things, and even empty domains [Anderson,CA]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
Predicate logic has to spell out that its identity relation '=' is an equivalent relation [Sommers]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Translating into quantificational idiom offers no clues as to how ordinary thinkers reason [Sommers]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
Sommers promotes the old idea that negation basically refers to terms [Sommers, by Engelbretsen]
5. Theory of Logic / E. Structures of Logic / 7. Predicates in Logic
Predicates form a hierarchy, from the most general, down to names at the bottom [Sommers]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Basic variables in second-order logic are taken to range over subsets of the individuals [Anderson,CA]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
Stop calling ∃ the 'existential' quantifier, read it as 'there is...', and range over all entities [Anderson,CA]
7. Existence / A. Nature of Existence / 2. Types of Existence
Do mathematicians use 'existence' differently when they say some entity exists? [Anderson,CA]
7. Existence / D. Theories of Reality / 2. Realism
Unfortunately for realists, modern logic cannot say that some fact exists [Sommers]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
We can distinguish 'ontological' from 'existential' commitment, for different kinds of being [Anderson,CA]
7. Existence / E. Categories / 1. Categories
Categories can't overlap; they are either disjoint, or inclusive [Sommers, by Westerhoff]
9. Objects / A. Existence of Objects / 4. Impossible objects
We cannot pick out a thing and deny its existence, but we can say a concept doesn't correspond [Anderson,CA]
's is non-existent' cannot be said if 's' does not designate [Anderson,CA]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Individuation was a problem for medievals, then Leibniz, then Frege, then Wittgenstein (somewhat) [Anderson,CA]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The notion of 'property' is unclear for a logical version of the Identity of Indiscernibles [Anderson,CA]
19. Language / B. Reference / 1. Reference theories
In standard logic, names are the only way to refer [Sommers]
28. God / C. Attitudes to God / 3. Deism
Clearly the gods ignore human affairs, or they would have given us justice [Thrasymachus]