We should start by congratulating both speakers for taking the trouble to discuss these important issues with our young people. And we should also give a pat on the back to the school for demonstrating the vision - and the courage - to conduct such a potentially controversial event on school premises during term time.

But we should reserve most of our praise for the girls themselves. They treated the session seriously, researched the background thoroughly and confidently raised a series of penetrating questions. They then handled the media with an aplomb that would put most of our ministers to shame.

One of the questioners challenged Professor Tai on the issue of proportionality. When black people in the United States adopted tactics of peaceful protest to press for their civil rights, it was because they had endured generations of injustice. Was the situation in Hong Kong really so grave and urgent? It was a good question, and one with which many would agree.

But, in a subtle way, rather than reducing the validity of Professor Tai's argument, the whole session made a convincing case for pressing ahead with universal suffrage. When teenagers show maturity to this degree, who can seriously argue that Hong Kong is not ready for democracy?

The Heep Yunn event was actually the second important civics lesson our community has received in recent weeks.

The first came when the American whistle-blower Edward Snowden revealed details of intelligence gathering on a massive scale around the globe.

When a private citizen sees someone breaking the law, he goes to the appropriate authority - the police, for example - to make a report. Even when the person breaking the law is himself a member of such an organisation, there is usually a channel for making complaints.

But where and to whom should the citizen report when he discovers that his own government as an institution is itself systematically acting unlawfully?

Snowden has taught us - or perhaps reminded us - that there is a higher authority than the government, and that is the people. So when you want to report a crime by the government, you report to the people, and the means to do that is via the media.

America's founding fathers recognised the vital role of the press in defending freedom and democracy. Benjamin Franklin would have understood Snowden's opposition to his own government's actions. "Those who would give up essential liberty, to purchase a little temporary safety, deserve neither liberty nor safety," he said. And was it not Thomas Jefferson who said, "Were it left to me to decide whether we should have a government without newspapers, or newspapers without a government, I should not hesitate a moment to prefer the latter".

The very first property I bought in Hong Kong was in a building named Monticello. There must be something in the water. It seems Hong Kong has become the new Land of the Free.