1 . Lia Thomas, a student at the University of Pennsylvania, is an excellent swimmer. She often beats her rivals by tens of seconds, breaking records. Her success is based on three things. One is natural talent. Another is persistent training. And the third is biology.

For although she identifies as a woman,Ms Thomas was born male.Since humans cannot change their sex (unlike their self-identified gender),she remains that way.On the eve of her biggest competition, Ms Thomas finds herself at the centre of the bad-tempered debate about whether trans women-males who identify as women-should compete in women’s sports.That,in turn,is part of a broader argument: should brute (纯粹的) biological facts sometimes override people’s deeply held feelings about their identities?

This newspaper believes it is almost always unfair to allow transgender women to compete in women’s sports.The advantages bestowed by male puberty (青春期) are so big that no amount of training or talent can enable female athletes to overcome them.Florence Griffith Joyner’s 100-metres world sprinting record has stood for three decades.A male matching it would not even make it to the Olympics, let alone the final.In 2016,at an American event for high-schoolers, four of the eight boys in the 100-metres final ran faster.

Much of the male advantage is granted by testosterone (睾丸素), a potent anabolic steroid whose levels rise sharply in male puberty.For many years,many sporting bodies, following the lead of the International Olympic Committee, hoped to deal with the issue by allowing trans women to compete in women’s events provided they took testosterone-suppressing drugs.But the science suggests this does not level the playing field.Suppressing testosterone in adults, it seems, does little to undo the advantages granted by a male adolescence.

Sports must therefore choose between inclusion and fairness; and they should choose fair play. That does not mean, as is sometimes claimed, that trans women would be barred from all sport.One way to make that clear would be to replace the “men’s” and “women’s” categories with “open” and “female” ones.The first would be open to all comers.The second would be restricted on the basis of biology.

Sport is public, and results can be measured objectively. That means the argument that the material facts of biology should sometimes outrank a person’s subjective sense of identity is easier to make. But bias exists, as a Republican bill in Florida to restrict “instruction” in schools about gender identity or sexual orientation makes plain.

That should be resisted. Most of the time,it costs little or nothing to respect people’s choices about how they wish to present themselves.In the rare cases where rights clash (不相容), society must weigh the balance sensitively and with open eyes.

2 . Both misinformation, which includes honest mistakes, and disinformation, which involves an intention to mislead, have had a growing impact on teenage students over the past 20 years. One tool that schools can use to deal with this problem is called media literacy education. The idea is to teach teenage students how to evaluate and think critically about the messages they receive. Yet there is profound disagreement about what to teach.

Some approaches teach students to distinguish the quality of the information in part by learning how responsible journalism works. Yet some scholars argue that these methods overstate journalism and do little to cultivate critical thinking skills. Other approaches teach students methods for evaluating the credibility of news and information sources, in part by determining the incentive of those sources. They teach students to ask: What encouraged them to create it and why? But even if these approaches teach students specific skills well, some experts argue that determining credibility of the news is just the first step. Once students figure out if it’s true or false, what is the other assessment and the other analysis they need to do?

Worse still, some approaches to media literacy education not only don’t work but might actually backfire by increasing students’ skepticism about the way the media work. Students may begin to read all kinds of immoral motives into everything. It is good to educate students to challenge their assumptions, but it’s very easy for students to go from healthy critical thinking to unhealthy skepticism and the idea that everyone is lying all the time.

To avoid these potential problems, broad approaches that help students develop mindsets in which they become comfortable with uncertainty are in need. According to educational psychologist William Perry of Harvard University, students go through various stages of learning. First, children are black-and-white thinkers—they think there are right answers and wrong answers. Then they develop into relativists, realizing that knowledge can be contextual. This stage is the one where people can come to believe there is no truth. With media literacy education, the aim is to get students to the next level—that place where they can start to see and appreciate the fact that the world is messy, and that’s okay. They have these fundamental approaches to gathering knowledge that they can accept, but they still value uncertainty.

Schools still have a long way to go before they get there, though. Many more studies will be needed for researchers to reach a comprehensive understanding of what works and what doesn’t over the long term. “Education scholars need to take an ambitious step forward,” says Howard Schneider, director of the Center for News Literacy at Stony Brook University.

3 . Hundreds of scientists, writers and academics sounded a warning to humanity in an open letter published last December: Policymakers and the rest of us must engage openly with the risk of global collapse. Researchers in many areas have projected the widespread collapse as “a credible scenario(情景) this century”.

A survey of scientists found that extreme weather events, food insecurity, and freshwater shortages might create global collapse. Of course, if you are a non-human species, collapse is well underway.

The call for public engagement with the unthinkable is especially germane in this moment of still-uncontrolled pandemic and economic crises in the world's most technologically advanced nations. Not very long ago, it was also unthinkable that a virus would shut down nations and that safety nets would be proven so disastrously lacking in flexibility.

The international scholars’ warning letter doesn't say exactly what collapse will look like or when it might happen. Collapseology, the study of collapse, is more concerned with identifying trends and with them the dangers of everyday civilization. Among the signatories(签署者) of the warning was Bob Johnson, the originator of the “ecological footprint” concept, which measures the total amount of environmental input needed to maintain a given lifestyle. With the current footprint of humanity, “it seems that global collapse is certain to happen in some form, possibly within a decade, certainly within this century,” Johnson said in an email.

“Only if we discuss the consequences of our biophysical limits,” the December warning letter says, “can we have the hope to reduce their speed, severity and harm”. And yet messengers of the coming disturbance are likely to be ignored. We all want to hope things will turn out fine. As a poet wrote,

Man is a victim of dope(麻醉品)

In the incurable form of hope.

The hundreds of scholars who signed the letter are intent(执着) on quieting hope that ignores preparedness. “Let's look directly into the issue of collapse,” they say, “and deal with the terrible possibilities of what we see there to make the best of a troubling future.”