On first reading of Ch.1, I got the impression that Harry was giving too much credit to the possibility of magic being real, since the prior must be such that even taking the effort to make the test would be incorrect. But now it’s blatantly obvious that the whole cognitive distortion event was caused by magic!
But this bizarre certainty… Harry was finding himself just expecting that, yes, a Hogwarts professor would show up and wave a wand and magic would come out. The strange certainty was making no effort to guard itself against falsification—wasn’t making excuses in advance for why there wouldn’t be a professor, or the professor would only be able to bend spoons.
Where do you come from, strange little prediction?
(Notice a reference to belief in belief, distinguishing true anticipation.)
I would say that while there are hypotheses with such low priors as to make it irrational to expend the effort to check them (and Harry would probably have assigned such a low probability to the existence of HP-style magic, and magical Britain, before he got the letter), one of these hypotheses being promoted specifically to your attention in the manner of the letter probably raises the prior to the point where it’s worth testing, at least.
The probability of magic is still vanishingly vanishingly low, but given how useful magic would be it might still be worth Harry’s time to test for it.
It’s also worth noting that the letter does not only provide several orders of magnitude jump in the prior for whether magic exists or not, but also provides a method of testing its existence that is much lower-cost than before (beforehand, Harry would have had to do some fairly strenuous things to break The Masquerade; with the letter in hand, he merely needs to send a reply.)
Talk to a prominent academic who gets lots of letters, and you’ll change your mind. My advisor developed this index to use before bothering with the letters he’s given. (The index itself is a joke, but the idea is real.)
A prominent academic receiving a letter that claims the existence of magic is less strong evidence than an elementary school aged kid receiving such a letter. In the absence of real magic, a prominent academic is quite likely to receive such letters from crackpots, whereas an elementary school aged kid is not.
In the absence of a pattern of such random crackpot letters, I would probably call a single letter sufficient evidence to make it worth testing. If that one didn’t pan out, or the next few, it stops being so. A specific oddity—such as an eleven-year-old receiving a letter purporting to be an invitation to attend a school of magic—is more evidence than an entry in a continuing pattern. (What would have happened, I wonder, if Mrs. Figg had not been present, and Harry had simply thrown out the letter as junk? Probably someone would have come anyway when no reply was received.)
If canon is any guide, it would have resulted in more letters. Lots and lots of letters. With Hagrid being sent after they don’t respond to the first thousand or so.
Based on my memory from the movie (which is more extreme than the book, but I forget how much), it would have been well worth responding to long before Hagrid arrived.
Harry’s father is supposedly a professor at Oxford. If “professor” has its UK meaning (= full professor, in US parlance), then being a professor at Oxford pretty much implies being a prominent academic: it’s the highest “normal” academic rank at the oldest and (roughly equally with Cambridge) most prestigious university in the country.
(“Associate professor” in the US is roughly equivalent to “reader” in the UK; “assistant professor” in the US is roughly equivalent to “lecturer” in the UK.)
As an American, then, I ask: is every full professor at Harvard a prominent academic? Perhaps at least as prominent as John Baez (who is more prominent, or at least better known to the public, than most of the full professors at his school but is at a much less prominent school).
The US is bigger, and has more first-rank universities, than the UK. So on the plausible hypothesis that the number of people who can be rightly called prominent in a given large community is roughly independent of the size of the community (since I’d expect it to be a matter of how many people one can remember easily) the threshold for prominence in the US should be higher.
(I take it that “prominent” here means something like “with a reasonable chance of being one person a crackpot picks on when s/he goes looking for an academic in the relevant field to contact about his/her crazy theories”. I don’t think this implies “well known to the general public”, though doubtless professors who are well known to the general public get more crank mail.)
I think that it should be strong evidence for ‘better known to the general public than most’, but not strictly implying that, nor good evidence for ‘well known in an absolute sense’ (although that depends on where you draw the line).
one of these hypotheses being promoted specifically to your attention in the manner of the letter probably raises the prior to the point where it’s worth testing, at least.
if you combined it with Petunia’s seemingly earnest insistence at having personally witnessed magic, it probably would
As far as simply testing the nature of reality, I’d still say no. However, Harry cares about his mother and wants his parents to stop fighting. This is what justifies the test, IMO.
I no longer remember what I thought when I first read Chapter 1, but now I don’t think that Harry should need this cognitive distortion (which I agree is there) in order to make the effort to test. He would propose (and then make) the test anyway, to try to settle the dispute between his parents.
On first reading of Ch.1, I got the impression that Harry was giving too much credit to the possibility of magic being real, since the prior must be such that even taking the effort to make the test would be incorrect. But now it’s blatantly obvious that the whole cognitive distortion event was caused by magic!
(Notice a reference to belief in belief, distinguishing true anticipation.)
I would say that while there are hypotheses with such low priors as to make it irrational to expend the effort to check them (and Harry would probably have assigned such a low probability to the existence of HP-style magic, and magical Britain, before he got the letter), one of these hypotheses being promoted specifically to your attention in the manner of the letter probably raises the prior to the point where it’s worth testing, at least.
The probability of magic is still vanishingly vanishingly low, but given how useful magic would be it might still be worth Harry’s time to test for it.
I hereby dub this class of argument Pascal’s Muggle
It’s also worth noting that the letter does not only provide several orders of magnitude jump in the prior for whether magic exists or not, but also provides a method of testing its existence that is much lower-cost than before (beforehand, Harry would have had to do some fairly strenuous things to break The Masquerade; with the letter in hand, he merely needs to send a reply.)
Talk to a prominent academic who gets lots of letters, and you’ll change your mind. My advisor developed this index to use before bothering with the letters he’s given. (The index itself is a joke, but the idea is real.)
A prominent academic receiving a letter that claims the existence of magic is less strong evidence than an elementary school aged kid receiving such a letter. In the absence of real magic, a prominent academic is quite likely to receive such letters from crackpots, whereas an elementary school aged kid is not.
Your point is valid, but remember that this elementary school aged kid is the son of a (prominent?) academic! It could be subtle ploy.
In the absence of a pattern of such random crackpot letters, I would probably call a single letter sufficient evidence to make it worth testing. If that one didn’t pan out, or the next few, it stops being so. A specific oddity—such as an eleven-year-old receiving a letter purporting to be an invitation to attend a school of magic—is more evidence than an entry in a continuing pattern. (What would have happened, I wonder, if Mrs. Figg had not been present, and Harry had simply thrown out the letter as junk? Probably someone would have come anyway when no reply was received.)
I so wish I had your address...
If canon is any guide, it would have resulted in more letters. Lots and lots of letters. With Hagrid being sent after they don’t respond to the first thousand or so.
Based on my memory from the movie (which is more extreme than the book, but I forget how much), it would have been well worth responding to long before Hagrid arrived.
You’re right; if there had been such a pattern, the narration would surely have said so.
Harry’s father is supposedly a professor at Oxford. If “professor” has its UK meaning (= full professor, in US parlance), then being a professor at Oxford pretty much implies being a prominent academic: it’s the highest “normal” academic rank at the oldest and (roughly equally with Cambridge) most prestigious university in the country.
(“Associate professor” in the US is roughly equivalent to “reader” in the UK; “assistant professor” in the US is roughly equivalent to “lecturer” in the UK.)
As an American, then, I ask: is every full professor at Harvard a prominent academic? Perhaps at least as prominent as John Baez (who is more prominent, or at least better known to the public, than most of the full professors at his school but is at a much less prominent school).
The US is bigger, and has more first-rank universities, than the UK. So on the plausible hypothesis that the number of people who can be rightly called prominent in a given large community is roughly independent of the size of the community (since I’d expect it to be a matter of how many people one can remember easily) the threshold for prominence in the US should be higher.
(I take it that “prominent” here means something like “with a reasonable chance of being one person a crackpot picks on when s/he goes looking for an academic in the relevant field to contact about his/her crazy theories”. I don’t think this implies “well known to the general public”, though doubtless professors who are well known to the general public get more crank mail.)
I think that it should be strong evidence for ‘better known to the general public than most’, but not strictly implying that, nor good evidence for ‘well known in an absolute sense’ (although that depends on where you draw the line).
Your advisor is that person? Lucky!
Yes, he’s a very nice guy to work with! (Although “was” is better than “is”, since I finished in 2006 and he’s now working on very different things.)
God no.
The letter alone would probably not make the existence of magic worth testing.
But if you combined it with Petunia’s seemingly earnest insistence at having personally witnessed magic, it probably would.
As far as simply testing the nature of reality, I’d still say no. However, Harry cares about his mother and wants his parents to stop fighting. This is what justifies the test, IMO.
AAnnd that the result is bound to be entertaining no matter what.
I no longer remember what I thought when I first read Chapter 1, but now I don’t think that Harry should need this cognitive distortion (which I agree is there) in order to make the effort to test. He would propose (and then make) the test anyway, to try to settle the dispute between his parents.