There Is No "True World" Beyond This One

A recurring issue involves the assertion by religion and Platonic-based philosophies that there is a "true world" of ideal forms or essences or divine beings beyond this one. Epicurean references relevant to the rejection of this contention include:

Epicurus' Letter to Herodotus

[40] And if there were not that which we term void and place and intangible existence, bodies would have nowhere to exist and nothing through which to move, as they are seen to move. And besides these two, nothing can even be thought of either by conception or on the analogy of things conceivable such as could be grasped as whole existences and not spoken of as the accidents or properties of such existences.

Lucretius Book One (Bailey)

[418] But now, to weave again at the web, which is the task of my discourse, all nature then, as it is of itself, is built of these two things: for there are bodies and the void, in which they are placed and where they move hither and thither. For that body exists is declared by the feeling which all share alike; and unless faith in this feeling be firmly grounded at once and prevail, there will be naught to which we can make appeal about things hidden, so as to prove aught by the reasoning of the mind. And next, were there not room and empty space, which we call void, nowhere could bodies be placed, nor could they wander at all hither and thither in any direction; and this I have above shown to you but a little while before.

[430] Besides these there is nothing which you could say is parted from all body and sundered from void, which could be discovered, as it were a third nature in the list. For whatever shall exist, must needs be something in itself; and if it suffer touch, however small and light, it will increase the count of body by a bulk great or maybe small, if it exists at all, and be added to its sum. But if it is not to be touched, inasmuch as it cannot on any side check anything from wandering through it and passing on its way, in truth it will be that which we call empty void. Or again, whatsoever exists by itself, will either do something or suffer itself while other things act upon it, or it will be such that things may exist and go on in it. But nothing can do or suffer without body, nor afford room again, unless it be void and empty space. And so besides void and bodies no third nature by itself can be left in the list of things, which might either at any time fall within the purview of our senses, or be grasped by any one through reasoning of the mind.