Combining Texts

All the ideas for 'Identity and Spatio-Temporal Continuity', 'A Free Will' and 'An Introduction to Modal Logic'

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12 ideas

1. Philosophy / C. History of Philosophy / 2. Ancient Philosophy / e. Late classical philosophy
In the third century Stoicism died out, replaced by Platonism, with Aristotelian ethics [Frede,M]
     Full Idea: By the second century CE Aristotelianism and Platonism had begun to eclipse Stoicism, and by the end of the third century Stoicism had no followers. All philosophers now opted for some form of Platonism, but including Aristotle's ethical principles.
     From: Michael Frede (A Free Will [1997], 04)
     A reaction: The idea that Aristotelian ethics dominated that period is new to me. Stoic influence remained strong in Augustine, and hence in Christianity.
In late antiquity nearly all philosophers were monotheists [Frede,M]
     Full Idea: I am inclined to think that almost all philosophers in late antiquity were monotheists.
     From: Michael Frede (A Free Will [1997], 08)
     A reaction: I'm not sure when late antiquity begins, in this remark. Maybe as early as 100 CE. Epictetus talks of Zeus as if he is supreme.
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell]
     Full Idea: A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0.
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: In the interpreted version of the logic, 1 and 0 would become T (true) and F (false). The procedure seems to be called nowadays a 'valuation'.
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]
     Full Idea: The Law of Transposition says that (P→Q) → (¬Q→¬P).
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: That is, if the consequent (Q) of a conditional is false, then the antecedent (P) must have been false.
4. Formal Logic / B. Propositional Logic PL / 4. Soundness of PL
The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell]
     Full Idea: An axiomatic system is most naturally consistent iff no thesis is the negation of another thesis. It can be shown that every axiom is valid, that the transformation rules are validity-preserving, and if a wff α is valid, then ¬α is not valid.
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: [The labels 'soundness' and 'consistency' seem interchangeable here, with the former nowadays preferred]
5. Theory of Logic / K. Features of Logics / 4. Completeness
A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]
     Full Idea: To say that an axiom system is 'weakly complete' is to say that every valid wff of the system is derivable as a thesis. ..The system is 'strongly complete' if it cannot have any more theses than it has without falling into inconsistency.
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: [They go on to say that Propositional Logic is strongly complete, but Modal Logic is not]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
'Ultimate sortals' cannot explain ontological categories [Westerhoff on Wiggins]
     Full Idea: 'Ultimate sortals' are said to be non-subordinated, disjoint from one another, and uniquely paired with each object. Because of this, the ultimate sortal cannot be a satisfactory explication of the notion of an ontological category.
     From: comment on David Wiggins (Identity and Spatio-Temporal Continuity [1971], p.75) by Jan Westerhoff - Ontological Categories §26
     A reaction: My strong intuitions are that Wiggins is plain wrong, and Westerhoff gives the most promising reasons for my intuition. The simplest point is that objects can obviously belong to more than one category.
16. Persons / F. Free Will / 2. Sources of Free Will
The idea of free will achieved universal acceptance because of Christianity [Frede,M]
     Full Idea: There is no doubt that the notion of a free will found almost universal acceptance owing to the influence of Christianity.
     From: Michael Frede (A Free Will [1997], 07)
     A reaction: This is presumably because a free will not only elevates us above the animals, qualifying us for immortality, but also gives us absolute and ultimate responsibility for our lives, which thus justifies either salvation or damnation.
The Stoics needed free will, to allow human choices in a divinely providential cosmos [Frede,M]
     Full Idea: The Stoics said that everything happens according to a divine providential plan, so they had to explain how this was compatible with human choices. They tried to do this with their doctrine of freedom and a free will.
     From: Michael Frede (A Free Will [1997], 10)
     A reaction: Epictetus made our ability to choose central to moral life, so he particularly needed (and thus created, it seems) this doctrine.
For Christians man has free will by creation in God's image (as in Genesis) [Frede,M]
     Full Idea: The Christian view, following Genesis, is that man is created in the image of God, and this is understood as crucially involving the idea that man has a free will in the image of God's will.
     From: Michael Frede (A Free Will [1997], 08)
     A reaction: The idea of free will evidently originated with Epictetus, but was taken up by Christians because it fitted doctrinal needs. Even Epictetus saw free will as originating in Zeus.
20. Action / B. Preliminaries of Action / 2. Willed Action / a. Will to Act
There is no will for Plato or Aristotle, because actions come directly from perception of what is good [Frede,M]
     Full Idea: Plato and Aristotle do not have a notion of a will, since for them a willing, a desire of reason, is a direct result of one's cognitive state: once one sees something to be good, one will it.
     From: Michael Frede (A Free Will [1997], 09)
     A reaction: The point is that their decisions are 'direct', whereas the will introduces the concept of a final arbiter which weighs up the desires, reasons and drives. The historical steps were first the meta-choosing, then the will as entity, then the will as free.
29. Religion / A. Polytheistic Religion / 4. Dualist Religion
The Gnostic demiurge (creator) is deluded, and doesn't care about us [Frede,M]
     Full Idea: The Gnostics thought the demiurge or creator pursues its own interests without regard for what this does to us, a being lacking in wisdom and goodness, as seen by its deluding itself into thinking that it is God, and demanding worship.
     From: Michael Frede (A Free Will [1997], Intro)
     A reaction: Frede mentions Irenaeus as a source of this view. The idea that the Great Being doesn't care about us seems a fairly accurate observation.