6 ideas
Nothing can be created out of nothing by divine power, because if things arose from nothing then any kind of thing could spring from anything at any time without seeds or seasons. The observed regularity of nature — that specific things grow only from specific origins in fixed times — proves matter is conserved and arises only from pre-existing material.
All things are composed of solid, eternal, indivisible particles moving through empty space, and nothing exists except these bodies and the void they move in. Without void there could be no motion, and without permanent solid units everything would have already dissolved into nothing across infinite past time.
As atoms fall through the void they occasionally deviate by the slightest, undetermined amount from their straight downward path. Without this swerve atoms would never collide to form anything, and it is the swerve that breaks the chain of mechanical fate and makes free will possible in living creatures.
Human misery is largely produced by terror of the gods and of divine punishment after death, fears rooted in ignorance of how nature actually works. Understanding that natural events have material causes — not divine wrath — dissolves this dread and is the real purpose of studying physics.
The soul is itself made of fine atoms that disperse at death, so consciousness ends entirely when the body dies. Since there is no one left to experience anything, death cannot be bad for the person who dies — to fear it is to imagine yourself still present at your own absence.
Perception works because objects constantly shed thin films of atoms that travel through the air and strike our sense organs, transmitting shape and color. This explains sight, dreams, and apparitions as physical impacts of real particles rather than messages from a spirit world.