It means people were debating intelligent design vs evolution at a time when people used to pee on their hands to clean them.

And at that time, they had no scientific methods to evaluate which side was correct, so the people who in hindsight were proven correct were able to be dismissed and forgotten by their peers and later generations.

Leucretius described light as made up of tiny indivisible parts that moved really quickly. The experiment proving the particle behavior of light is what got Einstein his Nobel prize 2,000 years later.

From this foundation Leucretius claimed that the sun, giving off light, was not an infinite resource and would one day itself die. This was only a few centuries after Anaxagoras was exiled from Athens for claiming the moon was a giant rock reflecting the sun's light.

In a single book are ideas literally over a thousand years before their time (in part due to intentional suppression by the church), and my guess is that until the comment above, you had no idea.

And that's unfortunate.

That's what it means.