Combining Texts

All the ideas for 'fragments/reports', 'Quaestiones Disputatae de Malo' and 'Introduction to the Philosophy of Mathematics'

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40 ideas

2. Reason / A. Nature of Reason / 1. On Reason
We are coerced into assent to a truth by reason's violence [Aquinas]
2. Reason / A. Nature of Reason / 4. Aims of Reason
The mind is compelled by necessary truths, but not by contingent truths [Aquinas]
3. Truth / A. Truth Problems / 3. Value of Truth
For the mind Good is one truth among many, and Truth is one good among many [Aquinas]
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
Showing a disproof is impossible is not a proof, so don't eliminate double negation [Colyvan]
Rejecting double negation elimination undermines reductio proofs [Colyvan]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Excluded middle says P or not-P; bivalence says P is either true or false [Colyvan]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Löwenheim proved his result for a first-order sentence, and Skolem generalised it [Colyvan]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Axioms are 'categorical' if all of their models are isomorphic [Colyvan]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Ordinal numbers represent order relations [Colyvan]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Intuitionists only accept a few safe infinities [Colyvan]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / j. Infinite divisibility
Infinitesimals were sometimes zero, and sometimes close to zero [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
Reducing real numbers to rationals suggested arithmetic as the foundation of maths [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
Transfinite induction moves from all cases, up to the limit ordinal [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Most mathematical proofs are using set theory, but without saying so [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Structuralism say only 'up to isomorphism' matters because that is all there is to it [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
If 'in re' structures relies on the world, does the world contain rich enough structures? [Colyvan]
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Knowledge may be based on senses, but we needn't sense all our knowledge [Aquinas]
14. Science / C. Induction / 6. Bayes's Theorem
Probability supports Bayesianism better as degrees of belief than as ratios of frequencies [Colyvan]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
Mathematics can reveal structural similarities in diverse systems [Colyvan]
14. Science / D. Explanation / 2. Types of Explanation / f. Necessity in explanations
Mathematics can show why some surprising events have to occur [Colyvan]
14. Science / D. Explanation / 2. Types of Explanation / m. Explanation by proof
Proof by cases (by 'exhaustion') is said to be unexplanatory [Colyvan]
Reductio proofs do not seem to be very explanatory [Colyvan]
If inductive proofs hold because of the structure of natural numbers, they may explain theorems [Colyvan]
Can a proof that no one understands (of the four-colour theorem) really be a proof? [Colyvan]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Mathematical generalisation is by extending a system, or by abstracting away from it [Colyvan]
16. Persons / F. Free Will / 3. Constraints on the will
If we saw something as totally and utterly good, we would be compelled to will it [Aquinas]
16. Persons / F. Free Will / 4. For Free Will
Because the will moves by examining alternatives, it doesn't compel itself to will [Aquinas]
Since will is a reasoning power, it can entertain opposites, so it is not compelled to embrace one of them [Aquinas]
The will is not compelled to move, even if pleasant things are set before it [Aquinas]
However habituated you are, given time to ponder you can go against a habit [Aquinas]
Nothing can be willed except what is good, but good is very varied, and so choices are unpredictable [Aquinas]
16. Persons / F. Free Will / 5. Against Free Will
We must admit that when the will is not willing something, the first movement to will must come from outside the will [Aquinas]
20. Action / B. Preliminaries of Action / 2. Willed Action / a. Will to Act
We don't have to will even perfect good, because we can choose not to think of it [Aquinas]
The will can only want what it thinks is good [Aquinas]
The will must aim at happiness, but can choose the means [Aquinas]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / g. Moral responsibility
Without free will not only is ethical action meaningless, but also planning, commanding, praising and blaming [Aquinas]
22. Metaethics / C. The Good / 1. Goodness / g. Consequentialism
Good applies to goals, just as truth applies to ideas in the mind [Aquinas]
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
Even a sufficient cause doesn't compel its effect, because interference could interrupt the process [Aquinas]
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]