"How can we measure the 'soul' of a lesson, and what happens when a lesson lacks 'soul'?"
A good proxy would be just looking at whether something was made by an artist, or a committee. E.g. Feynman's lectures were those of an artist, whereas most textbooks are created by a committee. (And then they get someone with a PhD to add their name as the author after the fact.) It's clear to me that Kahn's lessons are more in the style of the typical textbook, rather than in the style of someone like Feynman. You can't measure it, that's the point. If you could measure it then that's the first sign that something is wrong.
"But I guess since they are the highest castes, they are the ones who's mysticism we should adopt."
I'm not advocating the hindu model per se, only using them as an example of a society where schooling is framed in terms of a larger model... In their case one that includes work, marriage, wisdom seeking, preparation for death, etc. It's not clear to me that this is the right approach for western society, but I do think it's worth looking at for inspiration.
If you could measure it then that's the first sign that something is wrong.
In that case, I can tell you that you are very wrong. Khan's lessons have lots of soul. Not only soul, but also invisible dragons that breath the fire of knowledge!
I think Sagan's rant is cute, but ultimately wrong. And besides, when I talk about soul in this context, I'm obviously not talking about anything metaphysical. I'm just saying that his lessons are rather prosaic.
A good proxy would be just looking at whether something was made by an artist, or a committee. E.g. Feynman's lectures were those of an artist, whereas most textbooks are created by a committee. (And then they get someone with a PhD to add their name as the author after the fact.) It's clear to me that Kahn's lessons are more in the style of the typical textbook, rather than in the style of someone like Feynman. You can't measure it, that's the point. If you could measure it then that's the first sign that something is wrong.
"But I guess since they are the highest castes, they are the ones who's mysticism we should adopt."
I'm not advocating the hindu model per se, only using them as an example of a society where schooling is framed in terms of a larger model... In their case one that includes work, marriage, wisdom seeking, preparation for death, etc. It's not clear to me that this is the right approach for western society, but I do think it's worth looking at for inspiration.