And when that happens, all sorts of neat things happen.
当万事俱备的时候，就会出现良性循环。
One, the students can actually master the concepts, but they're also building their growth mindset,
首先，学生能够真正掌握知识，此外还能培养他们积极的心理，
they're building grit, perseverance, they're taking agency over their learning.
建立勇气和不屈不挠的精神，他们会对学习产生热情。
And all sorts of beautiful things can start to happen in the actual classroom.
在实际的课堂中，一切也慢慢开始走上正轨。
Instead of it being focused on the lecture, students can interact with each other.
学生们之间可以进行更多学习上的互动，而不必拘泥于专心听讲。
They can get deeper mastery over the material. They can go into simulations, Socratic dialogue.
他们能够更加深入地去掌握知识。他们能够模拟苏格拉底式对话。
To appreciate what we're talking about and the tragedy of lost potential here,
为了强化这一点，让大家体会无法激发潜能的遗憾，
I'd like to give a little bit of a thought experiment.
我想带大家进行一个思维小实验。
If we were to go 400 years into the past to Western Europe, which even then, was one of the more literate parts of the planet,
假设我们回到400年前的西欧，在当时就已经是地球上文明最发达的地区之一，
you would see that about 15 percent of the population knew how to read.
你会发现大概有15％的人口识字。
And I suspect that if you asked someone who did know how to read, say a member of the clergy,
估计当你去询问一个识字的人，比如一个神职人员，
"What percentage of the population do you think is even capable of reading?"
“你认为大概有多少人有识字的能力呢？”
They might say, "Well, with a great education system, maybe 20 or 30 percent."
他们也许会说：“嗯，基于这强大的教育体系，大概有个20%或30%吧。”
But if you fast forward to today, we know that that prediction would have been wildly pessimistic,
但如果你快进到当下，我们会发现那样的预测实在太悲观了，
that pretty close to 100 percent of the population is capable of reading.
现在几乎是人人都识字。
But if I were to ask you a similar question:
但是当我问你们一个类似的问题：
"What percentage of the population do you think is capable of truly mastering calculus,
“你们认为总人口中有多少是真正掌握微积分的，
or understanding organic chemistry, or being able to contribute to cancer research?"
或是真正懂有机化学的，或是有能力为癌症研究作出贡献的呢？”
A lot of you might say, "Well, with a great education system, maybe 20, 30 percent."
你们中的很多就会回答：“嗯，基于这强大的教育体系，大概有个20%或30%吧。”
