History is full of great rivalries: Athens versus Sparta, Lincoln versus Douglas, even the Roadrunner versus Wile E. Coyote.

Author Charles C. Mann describes a less familiar faceoff in his new book, The Wizard and the Prophet: Two Remarkable Scientists and Their Dueling Visions to Shape Tomorrows World. Published earlier this year, it has met with wide acclaim.

The wizard was Norman Borlaug, the father of the Green Revolution. The prophet was William Vogt, a believer in apocalyptic environmentalism. Mann has written a dual biography of these two men and their competing ideas about what the 21st century will bring.

Anybody who thinks about the future of food ought to read it.

Thinking about the future of food is how Mann, a science journalist, became interested in his topic. In a prologue, he mentions the birth of his daughter. I wandered outside for a while so that mother and child could rest, he writes. A thought popped into my head: When my daughter is my age, almost 10 billion people will be walking the earth.

Demographers say it will happen around 2050.

Ten billion mouths, I thought. How can they possibly be fed?

William Vogt

This vexing question prompted Mann to explore the lives of his subjects and recount them on the pages of his compelling book.

Borlaug (1914-2009) was an optimist who believed that science and affluence would provide solutions to our greatest problems. Vogt (1902-1968) was a pessimist who thought that affluence itself was a problem because it led to the depletion of resources.

Mann writes that as a young adult in the 1970s, he became a disciple of Vogt, convinced that the human enterprise would fall apart if our species didnt abruptly reverse course. He worried about famine, starvation, and mass deaths in an epic planetary breakdown.

Then he noticed something: These predictions of doom didnt come to pass.

One of the reasons why, Mann discovered, was the genius of Borlaug. A biologist from Iowa, Borlaug devoted his life to improving the food supply. He developed better seeds and helped farmers around the world adopt new practices. In 1970, he won the Nobel Peace Prize. Some people have claimed that because of Borlaugs agricultural innovations, a billion extra people are alive today.

Norman Borlaug

So in the 1980s, Mann altered his thinking: I became a Borlaugian, scoffing at the catastrophic scenarios I had previously embraced.

Yet he never quite shook the influence of Vogt. Although his head seems to tell him that Borlaug was correct, his heart keeps pulling him back to Vogt: My daughter, in college as I write, is headed into a future that seems ever more jostling and contentious, ever closer to overstepping social, physical, and ecological margins.

The bulk of the book focuses on four of the biggest dilemmas of the 21st century: farming, water, energy, and climate. Mann describes the state of play in each area, looking to Borlaug and Vogt for insights and trying to remain impartial. The Wizard and the Prophet, he writes, is a book about the future that makes no predictions.

Ill boldly go where Mann hasnt gone: Farmers will rise to the challenge of 2050 and those 10 billion mouths.

Thats my forecast, rooted in my experience as a farmer.Farmers are naturally optimistic. We have to be!

Im squarely in Borlaugs camp. I met Dr. Borlaug and was able to see first-hand his optimism, his belief in the power of agricultural technology and his passion for getting that technology into the hands of farmers.Science and technology help us grow more food every year. In recent decades, weve benefitted from the widespread adoption of GMOs. In the near future, innovative technologies including CRISPR and gene-editing techniques will enable new advances. Everything is more sustainable, too: With the advent of precision farming, informed by new types of data collection and guided by GPS satellites, were much smarter and clearly more efficient about how we use water, fertilizer, and fuel.

While we must guard against excessive optimismwell always face difficultieswere much better off when we allow Borlaug to inspire us than when we allow Vogt to frighten us.

This July will mark the 50th anniversary of Vogts death. Something tells me that if he had lived on, perhaps he would have come to appreciate the ability of the human race to confront its biggest tests.

There I go again, thinking like an optimist wizard rather than a pessimistic prophet.

In the end, it may come down to something as simple as this: Hope is better than despair.