Combining Texts

All the ideas for 'Phenomenalism', 'On the Algebra of Logic' and 'De arcanus motus'

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5 ideas

8. Modes of Existence / C. Powers and Dispositions / 1. Powers
12733 Because of the definitions of cause, effect and power, cause and effect have the same power [Leibniz]
     Full Idea: The primary mechanical axiom is that the whole cause and the entire effect have the same power [potentia]. ..This depends on the definition of cause, effect and power.
     From: Gottfried Leibniz (De arcanus motus [1676], 203), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 6
     A reaction: This is a useful reminder that if one is going to build a metaphysics on powers (which I intend to do), then the conservation laws in physics are highly relevant.
10. Modality / A. Necessity / 2. Nature of Necessity
12734 Every necessary proposition is demonstrable to someone who understands [Leibniz]
     Full Idea: Every necessary proposition is demonstrable, at least by someone who understands it.
     From: Gottfried Leibniz (De arcanus motus [1676], 203), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 6
     A reaction: This kind of optimism leads to the crisis of the Hilbert Programme in the 1930s. Gödel seems to have conclusively proved that Leibniz was wrong. What would Leibniz have made of Gödel?
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
14303 Truth-functional conditionals have a simple falsification, when A is true and B is false [Peirce]
     Full Idea: The utility of [truth-functional conditionals] is that it puts us in possession of a rule...[namely] The hypothetical proposition may be ...falsified by a single state of things, but only by one in which A [antecedent] is true and B [consequent] is false.
     From: Charles Sanders Peirce (On the Algebra of Logic [1895], p.218), quoted by Stephen Mumford - Dispositions
     A reaction: Personally I am rather more interested in verifying conditionals than in falsifying them. I certainly don't accept them until they are falsified, unless they have massive support from surrounding facts.
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
2614 Modern phenomenalism holds that objects are logical constructions out of sense-data [Ayer]
     Full Idea: Nowadays phenomenalism is held to be a theory of perception which says that physical objects are logical constructions out of sense-data.
     From: A.J. Ayer (Phenomenalism [1947], §1)
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
2615 The concept of sense-data allows us to discuss appearances without worrying about reality [Ayer]
     Full Idea: The introduction of the term 'sense-datum' is a means of referring to appearances without prejudging the question of what it is, if anything, that they are appearances of.
     From: A.J. Ayer (Phenomenalism [1947], §1)