Nothing from nothing ever was yet born.In other words, when we see things that we can't explain, we jump to a supernatural or divine explanation. The sun and moon? Gods. Shooting stars and lightning? Acts of the gods. Droughts and floods? Well, you get the idea.
Fear hold dominion over mortality
Only because, seeing in land and sky
So much the cause whereof no wise they know,
Men think Divinities are working there.
Lucretius doesn't agree.
More clearly what we seek: those elementsIt's all natural. There are explanations for everything without bothering any 'Divinities'. He said that everything is made of 'seeds'. We would call those seeds 'atoms'. He says that everything is made of these really small atoms, but not just atoms. He also says that different objects have different levels of void. That is, the space between the atoms isn't uniform between every object. In this, he is saying different objects have different densities. He also says that there must be a minimum size because an infinitely small seed violates mathematical theory.
From which alone all things created are,
And how accomplished by no tool of the Gods.
The theory of atoms is amazing for the time. Especially since it took so long to actually demonstrate the existence of atoms. You can see how later scientists would be driven to prove or disprove atomic theory. And part of the work of later readers was difficult because atomic theory had gotten connected to Lucretius insistence that there was no divine hand at work. Accept that everything is made of 'seeds' and you deny God.
How strange does that seem from our modern viewpoint?