Daniel Posted June 28 11 minutes ago, S:C said: How so? Can you explain please, Daniel? Finding a counter-example is often easiest by looking for the undisclosed assumptions. These assumptions possess possibilities which were not included when producing the assertion. In this case the assertion was simple subject ---> predicate. I introduced a "black-box" in-between the subject and the predicate then I considered what could be in this black-box? Is there anything I can add to the sequence of events which would possibly produce the outcome which is being denied. 14 minutes ago, S:C said: Still curious on how a mango seed becomes a apple tree in modal logic! See here: " ... The ability to bring back extinct animals ... " https://www.mybiosource.com/learn/future-of-cloning/ The same can be accomplished with a mango seed in order to produce an apple tree. MangoSeed ---> AppleTree = FALSE if there is nothing else occurring other than putting it in the ground. That's an assumption. Looking for the counter-example, I introduce a "black-box" in between the subject and the predicate. Then I postulate what could be in that black box which produces the desired outcome. In my mind it looks like this: MangoSeed ----> [ _______________ ] ---------> AppleTree = True ??? I solved it by introducing DNA manipulation into the "black-box" in a future possible world. MangoSeed ---> DNAManipulation ---> AppleTree = True. 2 Share this post Link to post Share on other sites
Daniel Posted June 28 25 minutes ago, S:C said: Westerners sometimes call it playing the devils advocate I think that's different. Devil's advocate is role-play in the form of: "... for the sake of argument let's say I disagree with you ... " In this case it's first expressing "I am absolutely certain", then later, "well,... my personal over arching philosophy moderates my certainty." Share this post Link to post Share on other sites
S:C Posted June 28 (edited) Quote Finding a counter-example is often easiest by looking for the undisclosed assumptions. These assumptions possess possibilities which were not included when producing the assertion. That too, was quite helpful and enlightening today! Thank you @Daniel ! Do you have advice for a good book that gives an entry into modal logic (… is there something like modal logic for dummies?) You explained it very well, I think it’s helpful for all sorts of assertions of people! Edited June 28 by S:C Share this post Link to post Share on other sites
S:C Posted June 28 (edited) 4 minutes ago, Daniel said: I think that's different. (…) In this case it's first expressing "I am absolutely certain", then later, "well,... my personal over arching philosophy moderates my certainty." I‘m not so sure anymore. Isn’t truth a questionable and sometimes even dubious concept, depending on the perspective, question, context and definitions? What’s it called in the vedas? I gotta look that up sometime… Edited June 28 by S:C Share this post Link to post Share on other sites
snowymountains Posted June 28 13 hours ago, Daniel said: Here you go. Zachar, male. Nekevah, female. Androgynos, having both male and female characteristics. Tumtum, lacking sexual characteristics. Aylonit hamah, identified female at birth but later naturally developing male characteristics. Aylonit adam, identified female at birth but later developing male characteristics through human intervention. Saris hamah, identified male at birth but later naturally developing female characteristics. Saris adam, identified male at birth and later developing female characteristics through human intervention. https://www.myjewishlearning.com/article/the-eight-genders-in-the-talmud/ Rav Ammi suggests, drawing on a pair of verses from Isaish 51, that Avraham and Sarah were in fact tumtumim, and Rabbi Nachman further imagines that Sarah was an aylonit. https://www.sefaria.org/sheets/263046?lang=bi Interesting. Regarding 6 & 8, how was human intervention defined in the age when the Talmud was written? Share this post Link to post Share on other sites
Maddie Posted June 28 (edited) 2 hours ago, S:C said: Still curious on how a mango seed becomes a apple tree in modal logic! But maybe we should take this elsewhere, I don’t want to occupy @Maddies thread here with topics leading astray and elsewhere… Maybe it takes apple hormones? 🤭 Edited June 28 by Maddie 3 Share this post Link to post Share on other sites
Daniel Posted June 28 (edited) 2 hours ago, S:C said: That too, was quite helpful and enlightening today! Thank you @Daniel ! Do you have advice for a good book that gives an entry into modal logic (… is there something like modal logic for dummies?) You explained it very well, I think it’s helpful for all sorts of assertions of people! You're very welcome. Sadly no. I'm not an expert. The only aspect of modal logic that is employed here is a loosening of the restrictions that the phenomena exist here and now. Modal logic permits consideration of what is possible. The universal qualifier "in any possible world" signals modal logic. Wikipedia has a decent article on it, if I recall tho. Edited June 28 by Daniel Share this post Link to post Share on other sites
Daniel Posted June 28 2 hours ago, S:C said: I‘m not so sure anymore. Isn’t truth a questionable and sometimes even dubious concept, depending on the perspective, question, context and definitions? What’s it called in the vedas? I gotta look that up sometime… It can be, but, rigorous language, as usual prevents ambiguity. The switch on the wall is either on or off, not both, not neither. Law of the excluded middle. That's the foundation. Share this post Link to post Share on other sites
Daniel Posted June 28 21 minutes ago, Maddie said: Maybe it takes apple hormones? 🤭 .... Too many jokes ... ... Mind is overflowing ... 1 Share this post Link to post Share on other sites
Daniel Posted June 28 1 hour ago, snowymountains said: Interesting. Regarding 6 & 8, how was human intervention defined in the age when the Talmud was written? Good question. I don't know. 1 Share this post Link to post Share on other sites
Maddie Posted June 28 https://www.nbcnews.com/nbc-out/out-news/texas-supreme-court-upholds-ban-gender-affirming-care-trans-youths-rcna159496 This is unfortunate 😔 🏳️⚧️ 1 Share this post Link to post Share on other sites
Cobie Posted June 28 (edited) The Texas Supreme Court upheld the state’s ban on gender-affirming care for transgender minors. Texas law considers residents who are 18 years old or older as adults. Edited June 28 by Cobie Share this post Link to post Share on other sites
Mark Foote Posted June 28 (edited) 7 hours ago, Daniel said: It can be, but, rigorous language, as usual prevents ambiguity. The switch on the wall is either on or off, not both, not neither. Law of the excluded middle. That's the foundation. About that switch. A hot topic, in the 1920's and 30's in mathematics: In his second problem, [Hilbert] had asked for a mathematical proof of the consistency of the axioms of the arithmetic of real numbers. To show the significance of this problem, he added the following observation: "If contradictory attributes be assigned to a concept, I say that mathematically the concept does not exist" (Reid p. 71) Thus, Hilbert was saying: "If p and ~p are both shown to be true, then p does not exist", and was thereby invoking the law of excluded middle cast into the form of the law of contradiction. And finally constructivists … restricted mathematics to the study of concrete operations on finite or potentially (but not actually) infinite structures; completed infinite totalities … were rejected, as were indirect proof based on the Law of Excluded Middle. Most radical among the constructivists were the intuitionists, led by the erstwhile topologist L. E. J. Brouwer (Dawson p. 49) The rancorous debate continued through the early 1900s into the 1920s; in 1927 Brouwer complained about "polemicizing against it [intuitionism] in sneering tones" (Brouwer in van Heijenoort, p. 492). But the debate was fertile: it resulted in Principia Mathematica (1910–1913), and that work gave a precise definition to the law of excluded middle, and all this provided an intellectual setting and the tools necessary for the mathematicians of the early 20th century: Out of the rancor, and spawned in part by it, there arose several important logical developments; Zermelo's axiomatization of set theory (1908a), that was followed two years later by the first volume of Principia Mathematica, in which Russell and Whitehead showed how, via the theory of types: much of arithmetic could be developed by logicist means (Dawson p. 49) Brouwer reduced the debate to the use of proofs designed from "negative" or "non-existence" versus "constructive" proof: According to Brouwer, a statement that an object exists having a given property means that, and is only proved, when a method is known which in principle at least will enable such an object to be found or constructed … Hilbert naturally disagreed. "pure existence proofs have been the most important landmarks in the historical development of our science," he maintained. (Reid p. 155) Brouwer refused to accept the logical principle of the excluded middle, His argument was the following: "Suppose that A is the statement "There exists a member of the set S having the property P." If the set is finite, it is possible—in principle—to examine each member of S and determine whether there is a member of S with the property P or that every member of S lacks the property P." (this was missing a closing quote) For finite sets, therefore, Brouwer accepted the principle of the excluded middle as valid. He refused to accept it for infinite sets because if the set S is infinite, we cannot—even in principle—examine each member of the set. If, during the course of our examination, we find a member of the set with the property P, the first alternative is substantiated; but if we never find such a member, the second alternative is still not substantiated. Since mathematical theorems are often proved by establishing that the negation would involve us in a contradiction, this third possibility which Brouwer suggested would throw into question many of the mathematical statements currently accepted. "Taking the Principle of the Excluded Middle from the mathematician," Hilbert said, "is the same as … prohibiting the boxer the use of his fists." "The possible loss did not seem to bother Weyl … Brouwer's program was the coming thing, he insisted to his friends in Zürich." (Reid, p. 149) In his lecture in 1941 at Yale and the subsequent paper, Gödel proposed a solution: "that the negation of a universal proposition was to be understood as asserting the existence … of a counterexample" (Dawson, p. 157) (Wikipedia, "Law of Excluded Middle", emphasis added) Have yer counter-examples ready, when asserting the negation of universal propositions. Edited June 28 by Mark Foote 1 Share this post Link to post Share on other sites
Maddie Posted June 29 12 hours ago, Cobie said: The Texas Supreme Court upheld the state’s ban on gender-affirming care for transgender minors. Texas law considers residents who are 18 years old or older as adults. The party that claims they want government out of people's lives basically took parents right to govern the healthcare of their child away. 1 1 Share this post Link to post Share on other sites
silent thunder Posted July 1 On 6/29/2024 at 5:54 AM, Maddie said: The party that claims they want government out of people's lives basically took parents right to govern the healthcare of their child away. Always so convenient when they want and insist on government intrusion. And it's usually on other's lives, not their own. 1 Share this post Link to post Share on other sites
Mark Foote Posted July 2 (edited) On 6/29/2024 at 3:16 AM, old3bob said: Trig is enough for me. Well, the point of the excerpt from Wikipedia was really that not everybody trusts logic that includes the law of the excluded middle, especially when it comes to infinite sets. The set of all sets that don't include themselves--does that include itself? Godel basically demonstrated that a set of logical axioms sufficient to generate everything that's known in mathematics must also generate contradictions. If the axioms don't generate contradictions, you can't generate everything that's known in mathematics from them. I got really lucky. After trig, I flunked the calculus qualifying exam at the local junior college, so I had to go back and take the "pre-calculus" they offered there. The JC taught "pre-calculus" (trig) based on set theory, they built up the theorems of trig from set theory. That's the way all of the mathematics courses at college were taught, except for calculus--from set theory. The first-year calculus that was offered at university was intended for engineers. The proofs were not rigorous, only "intuitive", and for a lot of people I know, the proofs that were offered were not intuitive at all! I had a hard time with it. I wound up being a math major, and when they taught calculus again for math majors with complete proofs based on set theory, I enjoyed it very much. Most of my friends did the trig that was memorization of theorems and formulas, didn't "get" the calculus that was similarly taught, and resented mathematics. Just to let you know, you were short-changed if you tried calculus and dropped out. It wasn't you but the system. As usual. We now return the thread to the actual topic, hopefully... Edited July 2 by Mark Foote 1 Share this post Link to post Share on other sites
Daniel Posted July 3 (edited) On 6/28/2024 at 3:32 PM, Mark Foote said: Have yer counter-examples ready, when asserting the negation of universal propositions. Mr. Mark!!!!! Hello. I see your activity on the forum. I apologize I haven't had the opportunity to say hello until now. I hope you're well. Thank you for the food for thought. Meat Quorn and potatoes, and a sizeable portion too. You're a gentleman and scholar. Counter-examples are my specialty. I'm universally hated for them all around the world. LOL. ? can you find me a counter-example for the universal proposition above ? ? pretty please ? Edited July 3 by Daniel Share this post Link to post Share on other sites
Daniel Posted July 3 37 minutes ago, Mark Foote said: The set of all sets that don't include themselves--does that include itself? Category theory... man. It's the way. Share this post Link to post Share on other sites
Daniel Posted July 3 38 minutes ago, Mark Foote said: We now return the thread to the actual topic, hopefully... Yes, please. I think I made to page 8. But before I head back to that spot, I'm planning to read your posts. Share this post Link to post Share on other sites
old3bob Posted July 3 10 hours ago, Mark Foote said: Well, the point of the excerpt from Wikipedia was really that not everybody trusts logic that includes the law of the excluded middle, especially when it comes to infinite sets. The set of all sets that don't include themselves--does that include itself? Godel basically demonstrated that a set of logical axioms sufficient to generate everything that's known in mathematics must also generate contradictions. If the axioms don't generate contradictions, you can't generate everything that's known in mathematics from them. I got really lucky. After trig, I flunked the calculus qualifying exam at the local junior college, so I had to go back and take the "pre-calculus" they offered there. The JC taught "pre-calculus" (trig) based on set theory, they built up the theorems of trig from set theory. That's the way all of the mathematics courses at college were taught, except for calculus--from set theory. The first-year calculus that was offered at university was intended for engineers. The proofs were not rigorous, only "intuitive", and for a lot of people I know, the proofs that were offered were not intuitive at all! I had a hard time with it. I wound up being a math major, and when they taught calculus again for math majors with complete proofs based on set theory, I enjoyed it very much. Most of my friends did the trig that was memorization of theorems and formulas, didn't "get" the calculus that was similarly taught, and resented mathematics. Just to let you know, you were short-changed if you tried calculus and dropped out. It wasn't you but the system. As usual. We now return the thread to the actual topic, hopefully... Interesting Mark, math can be fun and rewarding or convoluted and frustrating, a good teacher for it is helpful. 1 Share this post Link to post Share on other sites
Mark Foote Posted July 3 22 hours ago, Daniel said: Mr. Mark!!!!! Hello. I see your activity on the forum. I apologize I haven't had the opportunity to say hello until now. I hope you're well. Thank you for the food for thought. Meat Quorn and potatoes, and a sizeable portion too. You're a gentleman and scholar. Counter-examples are my specialty. I'm universally hated for them all around the world. LOL. ? can you find me a counter-example for the universal proposition above ? ? pretty please ? Hey, Daniel. Are you talking about mango-apple chutney, that's a sort of universal. Pub lunch counter accompaniment, Guiness! Share this post Link to post Share on other sites
Mark Foote Posted July 3 (edited) 22 hours ago, Daniel said: Category theory... man. It's the way. Doesn't sound like it, unless maybe you're doing algebraic topology. People talk on that thread about category theory and functional programming. I'm familiar with functional programming, but in practice, I find code that uses it mostly unintelligible. Maybe my lesser intellect, but a lot of people make a living re-inventing the wheel these days, and I'm not fond of unnecessary complication. Like, I never saw the point of data-base software, but Ellison has done very well. Edited July 3 by Mark Foote Share this post Link to post Share on other sites
liminal_luke Posted July 3 11 minutes ago, Mark Foote said: algebraic topology. I had a feeling this transgender question & answer thread was gonna be mindboggling. 3 Share this post Link to post Share on other sites