Thomas Malthus - Scarier Than Stephen King?

That idea came to me from The Return of Thomas Malthus - The Current:

"So what did Malthus say that was so terrible? He challenged the conventional view of human perfectibility that was in fashion during the aftermath of the French Revolution and the approach of a new century. He wrote in the realist spirit of Thucydides, Edmund Burke, and America's Founding Fathers. He worried that leisure time and prosperity would produce as much evil as good, and that mass happiness would always elude society. He was a profoundly moral philosopher sensitive to the travails of the human condition. His specific theory -- that population increases geometrically while food supplies increase only arithmetically -- was eventually proven wrong, because the settlement of the New World and the Industrial Revolution would add significantly to agricultural output. And our current interest in Malthus may, too, prove short-lived if a new green revolution, for example, sweeps Africa."

And if Malthus was right?