Combining Texts

All the ideas for 'Mathematical Methods in Philosophy', 'Summa totius logicae' and 'Sets, Aggregates and Numbers'

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23 ideas

2. Reason / B. Laws of Thought / 3. Non-Contradiction
From an impossibility anything follows [William of Ockham]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
A proposition is true if its subject and predicate stand for the same thing [William of Ockham]
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
Ockham had an early axiomatic account of truth [William of Ockham, by Halbach]
5. Theory of Logic / A. Overview of Logic / 9. Philosophical Logic
Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew]
5. Theory of Logic / G. Quantification / 1. Quantification
The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
How many? must first partition an aggregate into sets, and then logic fixes its number [Yourgrau]
Nothing is 'intrinsically' numbered [Yourgrau]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
Defining 'three' as the principle of collection or property of threes explains set theory definitions [Yourgrau]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
We can't use sets as foundations for mathematics if we must await results from the upper reaches [Yourgrau]
You can ask all sorts of numerical questions about any one given set [Yourgrau]
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Just as unity is not a property of a single thing, so numbers are not properties of many things [William of Ockham]
7. Existence / A. Nature of Existence / 1. Nature of Existence
If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew]
7. Existence / A. Nature of Existence / 3. Being / g. Particular being
The words 'thing' and 'to be' assert the same idea, as a noun and as a verb [William of Ockham]
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
Universals are single things, and only universal in what they signify [William of Ockham]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
If essence and existence were two things, one could exist without the other, which is impossible [William of Ockham]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew]
The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew]
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
Epistemic logic introduced impossible worlds [Horsten/Pettigrew]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew]
Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew]
19. Language / D. Propositions / 4. Mental Propositions
Some concepts for propositions exist only in the mind, and in no language [William of Ockham]