More comfortable online than out partying, post-Millennials are safer, physically, than adolescents have ever been. But they’re on the brink of a mental-health crisis.

One day last summer, around noon, I called Athena, a 13-year-old who lives in Houston, Texas. She answered her phone—she’s had an iPhone since she was 11—sounding as if she’d just woken up. We chatted about her favorite songs and TV shows, and I asked her what she likes to do with her friends. “We go to the mall,” she said. “Do your parents drop you off?,” I asked, recalling my own middle-school days, in the 1980s, when I’d enjoy a few parent-free hours shopping with my friends. “No—I go with my family,” she replied. “We’ll go with my mom and brothers and walk a little behind them. I just have to tell my mom where we’re going. I have to check in every hour or every 30 minutes.”

Venture capitalist Nick Hanauer points out the obvious: Low wages create and sustain poverty, not lousy schools. Hanauer encapsulates conventional wisdom:

"Once upon a time, America created a public-education system that was the envy of the modern world. No nation produced more or better-educated high-school and college graduates, and thus the great American middle class was built. But then, sometime around the 1970s, America lost its way. We allowed our schools to crumble, and our test scores and graduation rates to fall. School systems that once churned out well-paid factory workers failed to keep pace with the rising educational demands of the new knowledge economy. As America's public-school systems foundered, so did the earning power of the American middle class. And as inequality increased, so did political polarization, cynicism, and anger, threatening to undermine American democracy itself."

For most of my adult life, I’ve railed against “corporate capitalism”, “consumer capitalism” and “crony capitalism”. It took me a long time to see that the problem is not the adjective, but the noun.

While some people have rejected capitalism gladly and swiftly, I’ve done so slowly and reluctantly. Part of the reason was that I could see no clear alternative: unlike some anti-capitalists, I have never been an enthusiast for state communism. I was also inhibited by its religious status. To say “capitalism is failing” in the 21st century is like saying “God is dead” in the 19th. It is secular blasphemy. It requires a degree of self-confidence I did not possess.

But as I’ve grown older, I’ve come to recognise two things. First, that it is the system, rather than any variant of the system, which drives us inexorably towards disaster. Second, that you do not have to produce a definitive alternative to say that capitalism is failing. The statement stands in its own right. But it also demands another, and different, effort to develop a new system.

Capitalism’s failures arise from two of its defining elements. The first is perpetual growth. Economic growth is the aggregate effect of the quest to accumulate capital and extract profit. Capitalism collapses without growth, yet perpetual growth on a finite planet leads inexorably to environmental calamity.