Combining Texts

All the ideas for 'Mathematics and Indispensibility', 'fragments/reports' and 'Elements of Mathematical Logic'

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5 ideas

4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
Lukasiewicz's L3 logic has three truth-values, T, F and I (for 'indeterminate') [Lukasiewicz, by Fisher]
     Full Idea: In response to Aristotle's sea-battle problem, Lukasiewicz proposed a three-valued logic that has come to be known as L3. In addition to the values true and false (T and F), there is a third truth-value, I, meaning 'indeterminate' or 'possible'.
     From: report of Jan Lukasiewicz (Elements of Mathematical Logic [1928], 7.I) by Jennifer Fisher - On the Philosophy of Logic
     A reaction: [He originated the idea in 1917] In what sense is the third value a 'truth' value? Is 'I don't care' a truth-value? Or 'none of the above'? His idea means that formalization doesn't collapse when things get obscure. You park a few propositions under I.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / e. Ontological commitment problems
All scientific tests will verify mathematics, so it is a background, not something being tested [Sober]
     Full Idea: If mathematical statements are part of every competing hypothesis, then no matter which hypothesis comes out best in the light of observations, they will be part of the best hypothesis. They are not tested, but are a background assumption.
     From: Elliott Sober (Mathematics and Indispensibility [1993], 45), quoted by Charles Chihara - A Structural Account of Mathematics
     A reaction: This is a very nice objection to the Quine-Putnam thesis that mathematics is confirmed by the ongoing successes of science.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / k. Ethics from nature
The goal is rationality in the selection of things according to nature [Diogenes of Babylon, by Blank]
     Full Idea: Diogenes of Babylon defined the goal to be rationality in the selection and rejection of the things according to nature.
     From: report of Diogenes (Bab) (fragments/reports [c.180 BCE]) by D.L. Blank - Diogenes of Babylon
     A reaction: This captures the central Stoic idea quite nicely. 'Live according to nature', but this always meant 'live according to reason', because that is (as Aristotle had taught) the essence of our nature. This only makes sense if reason and nature coincide.
22. Metaethics / C. The Good / 1. Goodness / a. Form of the Good
The good is what is perfect by nature [Diogenes of Babylon, by Blank]
     Full Idea: Diogenes of Babylon defined the good as what is perfect by nature.
     From: report of Diogenes (Bab) (fragments/reports [c.180 BCE]) by D.L. Blank - Diogenes of Babylon
     A reaction: This might come close to G.E. Moore's Ideal Utilitarianism, but its dependence on the rather uneasy of concept of 'perfection' makes it questionable. Personally I find it appealing. I wish we had Diogenes' explanation.
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
Justice is a disposition to distribute according to desert [Diogenes of Babylon, by Blank]
     Full Idea: Diogenes of Babylon defined justice as the disposition which distributes to everyone what he deserves.
     From: report of Diogenes (Bab) (fragments/reports [c.180 BCE]) by D.L. Blank - Diogenes of Babylon
     A reaction: The questions that arise would be 'what does a new-born baby deserve?', and 'what do animals deserve?', and 'does the lowest and worst of criminals deserve anything at all?'