Combining Philosophers

All the ideas for Friedrich Engels, C. Anthony Anderson and Bernard Bolzano

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21 ideas

2. Reason / B. Laws of Thought / 1. Laws of Thought
The laws of thought are true, but they are not the axioms of logic [Bolzano, by George/Van Evra]
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]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
An aggregate in which order does not matter I call a 'set' [Bolzano]
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]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Bolzano wanted to reduce all of geometry to arithmetic [Bolzano, by Brown,JR]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
A truly infinite quantity does not need to be a variable [Bolzano]
6. Mathematics / C. Sources of Mathematics / 2. Intuition of Mathematics
Bolzano began the elimination of intuition, by proving something which seemed obvious [Bolzano, by Dummett]
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 / C. Structure of Existence / 1. Grounding / c. Grounding and explanation
Philosophical proofs in mathematics establish truths, and also show their grounds [Bolzano, by Correia/Schnieder]
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]
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]
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
Bolzano wanted to avoid Kantian intuitions, and prove everything that could be proved [Bolzano, by Dummett]
19. Language / D. Propositions / 1. Propositions
Bolzano saw propositions as objective entities, existing independently of us [Bolzano, by Potter]
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
Propositions are abstract structures of concepts, ready for judgement or assertion [Bolzano, by Correia/Schnieder]
A 'proposition' is the sense of a linguistic expression, and can be true or false [Bolzano]
19. Language / E. Analyticity / 2. Analytic Truths
The ground of a pure conceptual truth is only in other conceptual truths [Bolzano]
24. Political Theory / D. Ideologies / 11. Capitalism
Free markets lead to boom and bust, pointless middlemen, and alienated workers [Engels]