Inside Tahrir Square on Thursday, I met a carpenter named Mahmood whose left arm was in a sling, whose leg was in a cast and whose head was being bandaged in a small field hospital set up by the democracy movement. This was the seventh time in 24 hours that he had needed medical treatment for injuries suffered at the hands of government-backed mobs. But as soon as Mahmood was bandaged, he tottered off once again to the front lines.

That was Tahrir Square on Thursday: pure determination, astounding grit, and, at times, heartbreaking suffering.

Mr. Mubarak has disgraced the twilight of his presidency. His government appears to have unleashed a brutal crackdown – hunting down human rights activists, journalists and, of course, demonstrators themselves. As I arrived near the square in the morning, I encountered a line of Mr. Mubarak’s goons carrying wooden clubs with nails embedded in them.

At Tahrir Square’s field hospital (a mosque in normal times), 150 doctors have volunteered their services, despite the risk to themselves. Maged, a 64-year-old doctor who relies upon a cane to walk, told me that he hadn’t been previously involved in the protests, but that when he heard about the government’s assault on peaceful pro-democracy protesters, something snapped.

So early Thursday morning, he prepared a will and then drove 125 miles to Tahrir Square to volunteer to treat the injured. "I don’t care if I don’t go back," he told me. "I decided I had to be part of this. If I die, this is for my country." [Tearing up as I merely copy and paste this - Ed.]

The lion-hearted Egyptians I met on Tahrir Square are risking their lives to stand up for democracy and liberty, and they deserve our strongest support – and, frankly, they should inspire us as well. A quick lesson in colloquial Egyptian Arabic: Innaharda, ehna kullina Misryeen! Today, we are all Egyptians!

Pro-government thugs at Tahrir Square used clubs, machetes, swords and straight razors on Wednesday to try to crush Egypt’s democracy movement, but, for me, the most memorable moment of a sickening day was one of inspiration: watching two women stand up to a mob…

The two sisters stood their ground and explained calmly to the mob why they favored democratic reform and listened patiently to the screams of the pro-Mubarak mob. When the women refused to be cowed, the men lost interest and began to move on – and the two women continued to walk to the center of Tahrir Square.

I approached the women, told them I was awed by their courage, and asked why they had risked the mob’s wrath to come to Tahrir Square. "We need democracy in Egypt," Amal told me. "We just want what you have."

The events were sometimes presented by the news media as "clashes" between rival factions. But this was an organized government crackdown, relying on armed hoodlums.

Until their arrival, Tahrir Square had been remarkably peaceful, partly because pro-democracy volunteers checked I.D.’s and frisked everyone entering. One man, a suspected police infiltrator, was caught with a gun on Tuesday, and volunteers disarmed him and dragged him to an army unit – all while forming a protective cordon around him to keep him from being harmed.

It should be increasingly evident that Mr. Mubarak is not the remedy for the instability in Egypt; he is its cause. The road to stability in Egypt requires Mr. Mubarak’s departure, immediately.

For me, when I remember this sickening and bloody day, I’ll conjure not only the brutality that Mr. Mubarak seems to have sponsored but also the courage and grace of those Egyptians who risked their lives as they sought to reclaim their country.