Gottfried Wilhelm Leibniz [The Monadology, 64-66] wrote:
But the machines of nature, namely, living bodies, are still machines
in their smallest parts ad infinitum. It is this that constitutes the
difference between nature and art, that is to say, between the divine
art and ours. And the Author of nature has been able to employ this divine
and infinitely wonderful power of art, because each portion of matter is not
only infinitely divisible, as the ancients observed, but is also actually
subdivided without end, each part into further parts, of which each has
some motion of its own; otherwise it would be impossible for each portion
of matter to express the whole universe. Whence it appears that in the
smallest particle of matter there is a world of creatures, living beings,
animals, entelechies, souls. Each portion of matter may be conceived as
like a garden full of plants and like a pond full of fishes. But each
branch of every plant, each member of every animal, each drop of its
liquid parts is also some such garden or pond.
And though the earth and the air which are between the plants of the garden,
or the water which is between the fish of the pond, be neither plant nor
fish; yet they also contain plants and fishes, but mostly so minute as
to be imperceptible to us.
And Ockam (with Pier Damiani - De Divina Omnipotentia - and
Aristotle) states that not even God, who is in possession of
"potentia absoluta" - it means: miracles - not just of "potentia
ordinata" - usual physical laws, could erase the past, or re-write it.
Does it mean that, according to Ockam, simulations are forbidden?
It seems that Ockam (as the Aquinas and also Wyclif) thinks
that God could create the multiverse, or many universes.
Leibniz also wrote: "although the whole of this life were
said to be nothing but a dream and the physical world nothing but a
phantasm, I should call this dream or phantasm real enough if, using
reason well, we were never deceived by it.".