You can't negotiate with a pandemic.

A virus doesn't respond to threats, bluffs, wheedling or flattery. You can't change its behavior by setting deadlines. All you can really do is slow it down, work to find a vaccine or effective treatment, and hope for the best.

The spread of the COVID-19 virus in recent weeks has done much to reveal humanity's limited control over the world in which we live. The memo hasn't been received by President Trump, though. On Monday, his "15 days to stop the spread" effort — originally conceived to challenge Americans to radical action in the face of illness — suddenly became a deadline, after which the president will apparently take it upon himself to decide who among his fellow citizens will live and who will die.

Time and tide wait for no human. Neither, apparently, does the economy.

"We cannot let the cure be worse than the problem itself," the president said Monday afternoon, warning that he won't let "social distancing" get in the way of reviving America's suddenly cratered commerce. "At the end of the 15-day period, we'll make a decision as to which way we want to go, where we want to go, the timing, and essentially we're referring to the timing of the opening ... of our country."

Monday was also the first day the United States reported more than 100 deaths from the coronavirus. By the end of this week — by the end of the president's 15-day period — that number is likely to be much higher.

"Things are going to get worse before they get better," Surgeon General Jerome Adams told the Today show on Monday.

That's an argument for staying locked down for awhile yet. Indeed, there are two big problems with Trump's apparent desire to liberate the economy from the clutches of a government shutdown. The first is legal — the shutdown orders are taking place at the state and local levels; Trump can't override the decisions of governors and mayors in their spheres of authority. (He also can't order, say, the NBA to resume play.) The second is moral and psychological — there is unlikely to be much "pent-up demand" to jumpstart the economy if Americans remain terrified to go out, or if they're grieving lost friends and family for months to come. The best way to fight the economic damage of COVID-19 is to fight the virus itself.

Under those circumstances, it would be easier and safer simply to pay everybody to stay home, right?

It's clear, however, that Trump is done giving much credence to the medical officials advising him, and listening more to Fox News conservatives who are arguing the quarantine is too high a price to pay for keeping their fellow Americans — especially the older ones most vulnerable to the illness — alive and healthy.

"I'm not living in fear of COVID-19, I'm living in fear of what's happening to this country," Texas Lt. Gov. Dan Patrick, a Republican, said Monday night on Tucker Carlson's show, adding: "No one reached out to me and said, ‘As a senior citizen, are you willing to take a chance on your survival in exchange for keeping the America that all America loves for your children and grandchildren?' And if that's the exchange, I'm all in."

That is a particularly interesting comment coming from Patrick, who has made his name as a pro-life right-wing culture warrior. When a racist gunman killed 22 people at an El Paso Wal-Mart last year, Patrick blamed abortion and video games. "We have devalued life in this country," he said then. Now he is suggesting that some lives are more valuable than others. Why? Because preserving some lives requires a halt to economic activity.

Democrats, of course, have pushed back. "If it's public health versus the economy, the only choice is public health," New York Gov. Andrew Cuomo tweeted. "You cannot put a value on human life."

There is probably a third way. In reality, a pure "shelter in place" order by state and local governments will probably have a limited life span. Forget economics — after a bit, human nature dictates Americans are going to want to stretch their legs and even socialize a little bit. And that date is probably coming sooner than the 18 months some doctors say it will take to implement a working vaccine.

It is still possible to maintain some level of social distancing and other healthy practices under such circumstances. In China, for example, hundreds of movie theaters reopened on Monday. Residents are cautiously emerging — a friend of mine in Shanghai over the weekend posted pictures of residents having a rooftop dinner together: Everybody around the table was wearing a safety mask. That sort of quasi-quarantine, quasi-normal event will probably become a familiar sight in America sometime in the not-too-distant future.

Before that can happen here, though, the threat of COVID-19 will have to recede considerably. Rigorous testing and temperature-taking regimes will need to be in place. Masks will have to be much more widely available. But as long as the number of cases keeps increasing, as long as hospitals warn they are being overwhelmed and undersupplied in the face of the pandemic, it is best that everybody — including as many workers as humanly possible — shelter in place.

Even Donald Trump can't change that truth just by setting a deadline. The virus has a say in the matter.