Observe that the writing on the back of the Mirror is in runes, not any particular alphabet. The fact that Harry can read anything out of them at all suggests that there is an effect meant to make them ‘readable’ regardless of what languages / alphabets the reader knows. This effect was presumably placed by someone who knew what the Mirror does and wanted to make sure that knowledge was preserved even if languages changed and the history of the Mirror was lost.
But then why would someone want to obscure the answer by making those runes the Words of False Comprehension? The end result of having both effects in place is that readers get a simple puzzle in a language they know, hidden behind a magical effect that makes them believe they understand the runes without any further effort. What goal would motivate a great effort to make the puzzle solvable, but only if you realize it’s there to be solved?
My answer is that it’s not a test of “can you read backwards and fix some spacing in a language you know,” it’s a test of basic rationality skills. The word reversal and changed spacing is just to prevent bypassing the rationality test.
What would someone reading the back of the Mirror need to do, to solve the puzzle? Ask the fundamental question of rationality: “What do I think I know, and why do I think I know it?” Realize that their initial beliefs about the meaning of the runes are free-floating beliefs, ones that don’t connect to the rest of their beliefs and don’t constrain anticipations. Realize that the free-floating beliefs are useless, discard them, and look past the false feeling of comprehension. Find the real puzzle, possibly aided by hearing that the runes are Words of False Comprehension.
And then once they’ve found it and converted it to words they recognize, put in the effort to understand what the words actually mean and connect those words to the rest of their beliefs rather than guessing the teacher’s password. We know that “coherent extrapolated volition” has a specific technical meaning, but Harry doesn’t and is going to have to work it out from his knowledge of English and stories about the Mirror.
Also: “It is claimed by several authorities that the Mirror alone of all magics possesses a true moral orientation”.
So here are my predictions:
At the end of Chapter 109, Quirrell and Harry are trapped in an alternate plane generated by the Mirror. 65%
Harry and Quirrell are going to wind up on different sides of the Mirror. 60%
Confunded!Quirrell received a fake Stone. 50%
Quirrell’s conception of Dumbledore, as Quirrell used to Confund himself, lacks full human wish complexity. 80%
There is a magical ‘translation’ effect (not the False Comprehension effect, although both may be part of the same spell) on the runes on the Mirror which enables people to ‘read’ the runes. 95%
The Mirror is involved in a test meant to distinguish some subset of rationalists (not necessarily a proper subset) from other people. 80%
The Mirror is involved in a test meant to distinguish Light Rationalists from other people, under some conception of Light / Good. 75%
Conditional on the Mirror being involved in a test meant to distinguish some subset of rationalists (not necessarily a proper subset) from other people, passing the test grants some type of additional power (including from knowing more about the Mirror and therefore being better able to use it). 90%
Observe that the writing on the back of the Mirror is in runes, not any particular alphabet. The fact that Harry can read anything out of them at all suggests that there is an effect meant to make them ‘readable’ regardless of what languages / alphabets the reader knows. This effect was presumably placed by someone who knew what the Mirror does and wanted to make sure that knowledge was preserved even if languages changed and the history of the Mirror was lost.
But then why would someone want to obscure the answer by making those runes the Words of False Comprehension? The end result of having both effects in place is that readers get a simple puzzle in a language they know, hidden behind a magical effect that makes them believe they understand the runes without any further effort. What goal would motivate a great effort to make the puzzle solvable, but only if you realize it’s there to be solved?
My answer is that it’s not a test of “can you read backwards and fix some spacing in a language you know,” it’s a test of basic rationality skills. The word reversal and changed spacing is just to prevent bypassing the rationality test.
What would someone reading the back of the Mirror need to do, to solve the puzzle? Ask the fundamental question of rationality: “What do I think I know, and why do I think I know it?” Realize that their initial beliefs about the meaning of the runes are free-floating beliefs, ones that don’t connect to the rest of their beliefs and don’t constrain anticipations. Realize that the free-floating beliefs are useless, discard them, and look past the false feeling of comprehension. Find the real puzzle, possibly aided by hearing that the runes are Words of False Comprehension.
And then once they’ve found it and converted it to words they recognize, put in the effort to understand what the words actually mean and connect those words to the rest of their beliefs rather than guessing the teacher’s password. We know that “coherent extrapolated volition” has a specific technical meaning, but Harry doesn’t and is going to have to work it out from his knowledge of English and stories about the Mirror.
Also: “It is claimed by several authorities that the Mirror alone of all magics possesses a true moral orientation”.
So here are my predictions:
At the end of Chapter 109, Quirrell and Harry are trapped in an alternate plane generated by the Mirror. 65%
Harry and Quirrell are going to wind up on different sides of the Mirror. 60%
Confunded!Quirrell received a fake Stone. 50%
Quirrell’s conception of Dumbledore, as Quirrell used to Confund himself, lacks full human wish complexity. 80%
There is a magical ‘translation’ effect (not the False Comprehension effect, although both may be part of the same spell) on the runes on the Mirror which enables people to ‘read’ the runes. 95%
The Mirror is involved in a test meant to distinguish some subset of rationalists (not necessarily a proper subset) from other people. 80%
The Mirror is involved in a test meant to distinguish Light Rationalists from other people, under some conception of Light / Good. 75%
Conditional on the Mirror being involved in a test meant to distinguish some subset of rationalists (not necessarily a proper subset) from other people, passing the test grants some type of additional power (including from knowing more about the Mirror and therefore being better able to use it). 90%
My previous prediction comment is here.
Also, the subtle hints at reflective consistency are both funny and hints to Harry about the Mirror’s nature.