Combining Texts

All the ideas for 'Conceptual truth and metaphysical necessity', 'De Ente et Essentia (Being and Essence)' and 'Elements of Geometry'

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34 ideas

2. Reason / D. Definition / 5. Genus and Differentia
If definitions must be general, and general terms can't individuate, then Socrates can't be defined [Aquinas, by Cover/O'Leary-Hawthorne]
The definitions expressing identity are used to sort things [Aquinas]
2. Reason / E. Argument / 6. Conclusive Proof
Proof reveals the interdependence of truths, as well as showing their certainty [Euclid, by Frege]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / c. Derivations rules of PC
If you pick an arbitrary triangle, things proved of it are true of all triangles [Euclid, by Lemmon]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
Euclid's geometry is synthetic, but Descartes produced an analytic version of it [Euclid, by Resnik]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
An assumption that there is a largest prime leads to a contradiction [Euclid, by Brown,JR]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / m. One
A unit is that according to which each existing thing is said to be one [Euclid]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Postulate 2 says a line can be extended continuously [Euclid, by Shapiro]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Euclid relied on obvious properties in diagrams, as well as on his axioms [Potter on Euclid]
Euclid's parallel postulate defines unique non-intersecting parallel lines [Euclid, by Friend]
Euclid needs a principle of continuity, saying some lines must intersect [Shapiro on Euclid]
Euclid says we can 'join' two points, but Hilbert says the straight line 'exists' [Euclid, by Bernays]
Modern geometries only accept various parts of the Euclid propositions [Russell on Euclid]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / b. Greek arithmetic
Euclid's common notions or axioms are what we must have if we are to learn anything at all [Euclid, by Roochnik]
7. Existence / A. Nature of Existence / 3. Being / e. Being and nothing
If affirmative propositions express being, we affirm about what is absent [Aquinas]
8. Modes of Existence / B. Properties / 8. Properties as Modes
Properties have an incomplete essence, with definitions referring to their subject [Aquinas]
8. Modes of Existence / D. Universals / 6. Platonic Forms / d. Forms critiques
If the form of 'human' contains 'many', Socrates isn't human; if it contains 'one', Socrates is Plato [Aquinas]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
The principle of diversity for corporeal substances is their matter [Aquinas, by Cover/O'Leary-Hawthorne]
9. Objects / D. Essence of Objects / 1. Essences of Objects
It is by having essence that things exist [Aquinas]
9. Objects / D. Essence of Objects / 2. Types of Essence
Specific individual essence is defined by material, and generic essence is defined by form [Aquinas]
9. Objects / D. Essence of Objects / 4. Essence as Definition
The definition of a physical object must include the material as well as the form [Aquinas]
9. Objects / D. Essence of Objects / 5. Essence as Kind
Essence is something in common between the natures which sort things into categories [Aquinas]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
A simple substance is its own essence [Aquinas]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
Conceptual possibilities are metaphysical possibilities we can conceive of [Stalnaker]
The necessity of a proposition concerns reality, not our words or concepts [Stalnaker]
10. Modality / D. Knowledge of Modality / 3. A Posteriori Necessary
Critics say there are just an a priori necessary part, and an a posteriori contingent part [Stalnaker]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A 'centred' world is an ordered triple of world, individual and time [Stalnaker]
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
Definition of essence makes things understandable [Aquinas]
18. Thought / C. Content / 6. Broad Content
Meanings aren't in the head, but that is because they are abstract [Stalnaker]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
One view says the causal story is built into the description that is the name's content [Stalnaker]
19. Language / C. Assigning Meanings / 3. Predicates
The mind constructs complete attributions, based on the unified elements of the real world [Aquinas]
19. Language / C. Assigning Meanings / 10. Two-Dimensional Semantics
Two-D says that a posteriori is primary and contingent, and the necessity is the secondary intension [Stalnaker]
In one view, the secondary intension is metasemantic, about how the thinker relates to the content [Stalnaker]
26. Natural Theory / C. Causation / 5. Direction of causation
A cause can exist without its effect, but the effect cannot exist without its cause [Aquinas]