Combining Texts

All the ideas for 'fragments/reports', 'The Metaphysics of Space-Time Substantivalism' and 'Elements of Mathematical Logic'

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4 ideas

4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic

8942	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.

25. Social Practice / E. Policies / 5. Education / b. Education principles

13304	Learned men gain more in one day than others do in a lifetime [Posidonius]
	Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes.
	From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078
	A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book.

27. Natural Reality / C. Space / 4. Substantival Space

19035	General Relativity allows substantivalism about space-time - that it has independent properties [Hoefer]
	Full Idea: General Relativity describes space-time in a way that allows it to exist with determinate properties not reducible to the properties and relations of its material contents. Hence nearly all physicists and philosophers writing on GR are substantivalists.
	From: Carl Hoefer (The Metaphysics of Space-Time Substantivalism [1996], p.5), quoted by Barbara Vetter - Potentiality 7.3
	A reaction: I'm encouraged by this, as I instinctly favour substantivalism. Imagine removing all the objects from space-time, one by one. What happens as you approach the end of the task? Once they are removed, can they be replaced?

27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure

20820	Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]
	Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness.
	From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42
	A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them.