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How to Understand Things

nabeelqu.co

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Re: How to Understand Things

#91
post #88
post #74

Earlier quoted context omitted.

I pretty much told him the same: That we declared such statements to be true merely for convenience - it makes the proofs shorter. And that none of the theorems he would normally deal with would have a different "outcome" if we don't accept such statements - they'd still be valid theorems. But he won't be convinced until he formally studies logic. No idea when that will happen.

Well I have "formally" studied formal logic and he's in for a disappointment. Formal logic is a game, especially boolean logic, which has no grounding in truth, the world, or anything. Sometimes it's a useful game, but there's no inherent meaning behind it. Tell your friend that implication works that way because that's what we've assumed, nothing more, nothing less.

> Formal logic is a game, especially boolean logic, which has no grounding in truth, the world, or anything.

Thing is: He knows this. He's not a "beginner" who wants to learn a bit more. He just hasn't spent enough time pondering vacuously true statements, and is assuming there is more to it than there is, and hopes studying logic will shed some light. So he refuses to study analysis until he has time to study logic.

No doubt, if he ever gets to logic, he'll end up with more questions and branching off further and further. He'll never get around to analysis. But like the top level comment - he doesn't like it when people tell him not to bother.

Re: How to Understand Things

#92
post #91
post #88

Earlier quoted context omitted.

Well I have "formally" studied formal logic and he's in for a disappointment. Formal logic is a game, especially boolean logic, which has no grounding in truth, the world, or anything. Sometimes it's a useful game, but there's no inherent meaning behind it. Tell your friend that implication works that way because that's what we've assumed, nothing more, nothing less.

> Formal logic is a game, especially boolean logic, which has no grounding in truth, the world, or anything. Thing is: He knows this. He's not a "beginner" who wants to learn a bit more. He just hasn't spent enough time pondering vacuously true statements, and is assuming there is more to it than there is, and hopes studying logic will shed some light. So he refuses to study analysis until he has time to study logic.…

Though not implication, there is some reasoning to some other vacuously true statements. Take for example:

All purple cows are smart.

This statement is true, because the set of purple cows is empty. It might seem, odd, but it's because we can rephrase it as:

There does not exist a purple cow that is not smart.

When you phrase it like that, I think most people would intuitively agree that it should evaluate to true. In other words, to preserve symmetry between the universal and existential qualifiers, you need the first statement to also be true. Without the ability to transform "exists" into "foralls" would make first order predicate logic pretty much useless. In addition, if the emptiness of a set actually changed how the quantifiers worked, it would be a big problem: breaking referential transparency, if you will.

I don't recall there being a similar justification for implication in boolean logic, but I think the reasoning is similar. Hope that helps!

Re: How to Understand Things

#93

Great post. Personal anecdote: I don't think I really understood anything in school, but I was decent at going through the motions of carrying out certain methods and recalling certain facts when I needed to. I went on to study Maths at university, and for most of my first year, I had the same surface level "methods + facts" knowledge that got me through school. After some studying, I could recite definitions and the…

I felt the same exact way trying to memorize molecular formulas in organic chemistry, being able to visualize the molecules and some outlandish pneumonics really allowed me to force my brain to make memories that I forgot over time however I gained the ability to "see" the molecules in my mind and deriving the formula became trivial.

Creating really unique pneumonics works similar to how you can recall when something happened out of the ordinary or have a "sixth" sense where you subconsciously can sense something is off in an otherwise ordinary situation or encounter. If I had to guess, this might be an evolved human survival mechanism that helped our ancestors detect and avoid dangerous/deadly situation.

I wonder what other evolutionary mechanism we can hack to encode concepts more deeply. I know spaced repetition is the mainstream approach via flashcards/ankii type apps. I think pneumonics blended with spaced repetition is the most practical methodology. Thoughts?

Re: How to Understand Things

#94
post #53

> This quality of “not stopping at an unsatisfactory answer” deserves some examination. > This requires a lot of intrinsic motivation, because it’s so hard; so most people simply don’t do it. It also requires self-confidence, persuasiveness, and social power. Without these traits, your attempts to really understand something will be dismissed as "overthinking things" or "trying to understand the universe". Those arou…

There are both extremes, and best not to be at either one of them. Example: I forget the name of the principle, but in mathematics the statement "P implies Q" is considered true if P can never be true. As an example, let P be "George Washington was a woman" and Q be "Queen Elizabeth is a man". Then the statement "If GW was a woman, then QE is a man" is considered to be a true statement. I have a friend who refuses to…

> the statement "P implies Q" is considered true if P can never be true. As an example, let P be "George Washington was a woman" and Q be "Queen Elizabeth is a man". Then the statement "If GW was a woman, then QE is a man" is considered to be a true statement.

> I have a friend who refuses to accept that such a statement should be considered "true".

This is a weird thing to refuse to accept, since it is an ordinary part of vernacular English, a common way of dismissing an assertion as false.

"If that guy graduated high school, I'm the King of England."

Re: How to Understand Things

#95
post #92
post #91

Earlier quoted context omitted.

> Formal logic is a game, especially boolean logic, which has no grounding in truth, the world, or anything. Thing is: He knows this. He's not a "beginner" who wants to learn a bit more. He just hasn't spent enough time pondering vacuously true statements, and is assuming there is more to it than there is, and hopes studying logic will shed some light. So he refuses to study analysis until he has time to study logic.…

Though not implication, there is some reasoning to some other vacuously true statements. Take for example: All purple cows are smart. This statement is true, because the set of purple cows is empty. It might seem, odd, but it's because we can rephrase it as: There does not exist a purple cow that is not smart. When you phrase it like that, I think most people would intuitively agree that it should evaluate to true. I…

> I don't recall there being a similar justification for implication in boolean logic, but I think the reasoning is similar.

You can apply a similar equivalence, the contrapositive. Using the same example I gave sidethread:

0. (Premise - I wish to snottily imply that "that guy" did not graduate from high school.)

1. "If that guy graduated from high school, I'm the King of England."

(1) is exactly equivalent to (2):

2. "If I'm not the King of England, that guy didn't graduate from high school."

A positive proposition in (1) is negative in (2), and vice versa. But they are the same thing; if one is defined, the other is also defined.

Re: How to Understand Things

#96
post #57

Great post. Personal anecdote: I don't think I really understood anything in school, but I was decent at going through the motions of carrying out certain methods and recalling certain facts when I needed to. I went on to study Maths at university, and for most of my first year, I had the same surface level "methods + facts" knowledge that got me through school. After some studying, I could recite definitions and the…

The university I went to offered open book/note exams for almost all courses. It literally didn't even matter how much you memorized... open book tests didn't make anything easier. you need to understand or fail. I'm not into showing off ranking or pedigree but I do genuinely believe that the higher the pedigree your school the more likely the exams will be harder and require total understanding and even creativity o…

Rote memorization tests are the easiest to make and grade, both in terms of simple instructor effort as well as in terms of fairness and lack of ambiguity.

In Asia it is common for schools to solely grade base on multiple choice exams which promote cramming and memorization. But in the US I would be shocked if a program that only operated that way was accredited. I would argue students who simply memorize things are trying to hack their way to an unearned grade. The goal of higher education is supposed to be to reach higher levels of Bloom's taxonomy, beyond the rote stuff done in primary and secondary school.

Re: How to Understand Things

#97
post #44

Earlier quoted context omitted.

It didn't work for the GP. That makes it poisonous and evil. I've seen this sentiment way too much on HN. X didn't work for me, therefore X is a scam, its perpetrators are evil sociopaths, and if it worked for you you're a cog in the machine, man .

I'm a believer in individual learning styles, and hard as it is for me to understand personally, I do recognize that lots of people may learn best by lecture and drill. I certainly don't think bad of them for it. but many more people are not suited for this, and forcing them through the education system as it exists does them great harm, and I empathize strongly with them

Lecture and drill has been out of vogue for decades. The hot thing is active learning and high-impact practices. And frankly it has the opposite problem of dragging the class down to the slowest common denominator, wasting the opportunity to teach more to the high-achievers.

Re: How to Understand Things

#98

Oh my lord, why is Jesus in that list?

because it's actually quite relevant. The quality that the author is talking about is simply faith. Genuine intellectual activity is the recognition that there is a gap between how you understand the world and that there is is a more genuine degree of understanding to be found. Because there's no guarantee of success the attitude one needs to adopt is the same attitude a believer needs to have, which is to take a lea…

The OP goes into some detail on the essentialness of honesty and integrity when it comes to inquiry. Without both, your pursuit of deep understanding will short-circuit. The best way I know to overlook truth is to willfully presume you know something, especially something unknowable. And that's faith. To exercise faith, you must stop questioning, shut your eyes, and jump into the abyss. You stop thinking. If some sort of understanding arises from faith, it most certainly is not the fruit of intellectual pursuit.

Re: How to Understand Things

#99
Huge fan of this kind of thinking.

I try to recommend this technique with software all the time. Basically instead of the workflow bring this

1) follow some tutorial online 2) integrate into real work

I do

1) follow some tutorial online 2) spend an hour to see how I can break it 3) integrate into real work

That step two does all sorts of wonderful things like helping you understand failure modes, better understand quality, make it easier to debug. You get the same knowledge over time by doing "real work", but it is much much more efficient this way :)

Re: How to Understand Things

#100
> Moreover, I have noticed that these ‘hardware’ traits vary greatly in the smartest people I know -- some are remarkably quick thinkers, calculators, readers, whereas others are ‘slow’.

This strikes a chord. I am much more of a nerd than my girlfriend, but I notice at almost every opportunity that she's a much quicker thinker and a much better learner than I am. I have studied math and computer science, but she regularly out-thinks me in puzzles, even when they are math-related.

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