Combining Texts

All the ideas for 'fragments/reports', 'On Second-Order Logic' and 'works'

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


20 ideas

5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley]
Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
'∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Why should compactness be definitive of logic? [Boolos, by Hacking]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Many concepts can only be expressed by second-order logic [Boolos]
7. Existence / A. Nature of Existence / 3. Being / a. Nature of Being
The concept of being has only one meaning, whether talking of universals or of God [Duns Scotus, by Dumont]
Being (not sensation or God) is the primary object of the intellect [Duns Scotus, by Dumont]
8. Modes of Existence / D. Universals / 4. Uninstantiated Universals
Duns Scotus was a realist about universals [Duns Scotus, by Dumont]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
Scotus said a substantial principle of individuation [haecceitas] was needed for an essence [Duns Scotus, by Dumont]
9. Objects / D. Essence of Objects / 2. Types of Essence
Avicenna and Duns Scotus say essences have independent and prior existence [Duns Scotus, by Dumont]
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
Certainty comes from the self-evident, from induction, and from self-awareness [Duns Scotus, by Dumont]
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / b. Direct realism
Scotus defended direct 'intuitive cognition', against the abstractive view [Duns Scotus, by Dumont]
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
Augustine's 'illumination' theory of knowledge leads to nothing but scepticism [Duns Scotus, by Dumont]
16. Persons / F. Free Will / 2. Sources of Free Will
The will retains its power for opposites, even when it is acting [Duns Scotus, by Dumont]
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]
28. God / A. Divine Nature / 2. Divine Nature
The concept of God is the unique first efficient cause, final cause, and most eminent being [Duns Scotus, by Dumont]
28. God / B. Proving God / 3. Proofs of Evidence / a. Cosmological Proof
We can't infer the infinity of God from creation ex nihilo [Duns Scotus, by Dumont]