It’s nice to see people smiling again. They may have been smiling all this time, but for the last year most of the people I would see in my walks around Portland were wearing masks that covered half of their faces.

But now the Centers for Disease Control and Prevention no longer recommends outdoor masking up for fully vaccinated people, and the faces have  reappeared.

I wore my mask, even though I hated it. My nose gets runny and my glasses fog up.

I had read enough to question whether mask wearing was really necessary outdoors when you weren’t in close contact with others. But I felt a responsibility to cover my mouth and nose when I was out on the street because of the message it sent.

The mask said: I take this seriously; I’m following the rules, not just this one but all of them; I’m doing what I can to protect your health; We’re all in this together.

So, the mask served a political purpose, the way Aristotle meant the word when he wrote, that “man, by nature, is a political animal.” Our ability to speak makes it possible for us to cooperate with each other, he reasoned in “Politics.” And wearing a mask while walking down the street was a kind of speech.

But the masks also became political speech in another way. It got caught up in the 2020 presidential campaign. Defying the public health protocols became a signal for supporters of Donald Trump, who wanted to downplay the pandemic that was killing 1,000 people a day because of the effect such bad news could have on the outcome of the election.

Not wearing a mask was supposed to show independence of thought, and distrust of experts in all fields who tell you to ignore what you see with your own eyes. As a result, a lot of people got sick needlessly, and thousands of them died.

Some are making the same political point by refusing a vaccine. Maine’s hospitals are seeing a surge of seriously ill people who have not been vaccinated. Refusing the vaccine has become political, just as refusing to wear a mask did. More than 40 percent of Trump voters tell pollsters that they won’t accept a vaccine because they don’t trust the pharmaceutical companies that developed it, the government scientists who approved it or the news media that told them about it.

Me, I do trust all those institutions, even though I know that they have all been wrong in the past. The pharmaceutical industry made billions selling opioids, claiming that people in pain could not become addicted. The Food and Drug Administration has had to recall medicines it had previously approved when they proved to be dangerous.

And anybody who remembers the WMD stories from 2003 knows that reporters are only as good as their sources.

But I still trust them on this.

I don’t think I’m smarter than the experts, which is why I let the pilot fly the plane and let the dentist drill my cavities. (I did attempt to cut my own hair for a while during the pandemic, and the results were, let’s just say, not good.)

So, as soon as I read in the Portland Press Herald that I was eligible to receive a vaccine for an invisible virus that had not killed anyone I knew personally, I eagerly signed up to let a stranger inject a clear liquid into my arm. And then three weeks later, I let them do it again.

How do I know that they weren’t injecting me with plain water? How do I know it wasn’t poison?

How do I know they weren’t installing “nanoparticle” robots with two-way 5G antennae, as former Yarmouth physician-turned-conspiracy peddler Christiane Northrup has claimed?

The answer is: I don’t really know, and I can’t. At some point I have to trust someone, and I come down on the side of the public health professionals. When the problems are big, “political animals” have to put aside their individual senses and use their ability to cooperate.

The mask is in my pocket for when I have to go inside, but I hope the message is still the same: We’re all in this together.