Combining Philosophers

All the ideas for Alex Orenstein, Gerhard Gentzen and Sebastian Gardner

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30 ideas

1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / c. Eighteenth century philosophy
Hamann, Herder and Jacobi were key opponents of the Enlightenment [Gardner]
Kant halted rationalism, and forced empiricists to worry about foundations [Gardner]
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
Only Kant and Hegel have united nature, morals, politics, aesthetics and religion [Gardner]
2. Reason / E. Argument / 2. Transcendental Argument
Transcendental proofs derive necessities from possibilities (e.g. possibility of experiencing objects) [Gardner]
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Sentential logic is consistent (no contradictions) and complete (entirely provable) [Orenstein]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
Axiomatization simply picks from among the true sentences a few to play a special role [Orenstein]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
S4: 'poss that poss that p' implies 'poss that p'; S5: 'poss that nec that p' implies 'nec that p' [Orenstein]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Unlike elementary logic, set theory is not complete [Orenstein]
4. Formal Logic / G. Formal Mereology / 1. Mereology
Mereology has been exploited by some nominalists to achieve the effects of set theory [Orenstein]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna]
The logical connectives are 'defined' by their introduction rules [Gentzen]
Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen]
5. Theory of Logic / G. Quantification / 1. Quantification
Traditionally, universal sentences had existential import, but were later treated as conditional claims [Orenstein]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
The substitution view of quantification says a sentence is true when there is a substitution instance [Orenstein]
5. Theory of Logic / H. Proof Systems / 4. Natural Deduction
Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Modern geoemtry is either 'pure' (and formal), or 'applied' (and a posteriori) [Gardner]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
The whole numbers are 'natural'; 'rational' numbers include fractions; the 'reals' include root-2 etc. [Orenstein]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
The logicists held that is-a-member-of is a logical constant, making set theory part of logic [Orenstein]
7. Existence / C. Structure of Existence / 6. Fundamentals / c. Monads
Leibnizian monads qualify as Kantian noumena [Gardner]
7. Existence / E. Categories / 3. Proposed Categories
Just individuals in Nominalism; add sets for Extensionalism; add properties, concepts etc for Intensionalism [Orenstein]
14. Science / B. Scientific Theories / 1. Scientific Theory
The Principle of Conservatism says we should violate the minimum number of background beliefs [Orenstein]
19. Language / A. Nature of Meaning / 10. Denial of Meanings
People presume meanings exist because they confuse meaning and reference [Orenstein]
19. Language / C. Assigning Meanings / 3. Predicates
Three ways for 'Socrates is human' to be true are nominalist, platonist, or Montague's way [Orenstein]
19. Language / D. Propositions / 4. Mental Propositions
If two people believe the same proposition, this implies the existence of propositions [Orenstein]
21. Aesthetics / A. Aesthetic Experience / 1. Aesthetics
Aesthetics presupposes a distinctive sort of experience, and a unified essence for art [Gardner]
21. Aesthetics / B. Nature of Art / 7. Ontology of Art
Art works originate in the artist's mind, and appreciation is re-creating this mental object [Gardner]
21. Aesthetics / C. Artistic Issues / 5. Objectivism in Art
Aesthetic objectivists must explain pleasure being essential, but not in the object [Gardner]
22. Metaethics / B. Value / 1. Nature of Value / d. Subjective value
Aesthetic judgements necessarily require first-hand experience, unlike moral judgements [Gardner]