"There is nothing which in itself is just one thing: nothing which you could rightly
call anything or any kind of thing. If you call a thing large, it will reveal itself as small,
and if you call it heavy, it is liable to appear as light, and so on with everything,
because nothing is anything or any kind of thing. What is really true is this:
the things of which we naturally say that they 'are,' are in process of coming-to-be,
as the result of movement and change and blending with one another.
We are wrong when we say they 'are,' since nothing ever is, but everything is coming-to-be."
Plato, Theaetetus 152d-e
Our world as we experience it
is an illusion like shadows on a wall
Plato, Republic 514a-519c.5
Plato, Republic 507b–509c