THE FOLK THEORY OF GENERAL KINDS:
Every particular thing is a kind of thing.
THE FOLK THEORY OF ESSENCES:
Every kind of thing has common properties shared by all particulars of that thing.
Plato, Euthyphro 6d-e
Plato, Symposium 211c-d
Proclus, Commentary on Plato’s Timaeus 1.345.18
As Alexander reports, Theophrastus, in the first book of his
Inquiry into Nature, sets out Parmenides’ argument as follows:
“What is other than what-is, is not; what-is-not is nothing; therefore what-is is one”...
Simplicius, Commentary on Aristotle’s Physics 115.11-13
"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
"Either [tallness] gives way and withdraws as its opposite
shortness approaches, or it has already ceased to exist by the time
that the other arrives."
Plato, Phaedo 102b.5-d
Plato, Phaedo 74a-75a
Our world as we experience it
is an illusion like shadows on a wall
Plato, Republic 514a-519c.5
"This reality, then, that gives their truth to the objects of knowledge
and power of knowing to the knower, you must say is the idea of good,
and you must conceive it as being the cause of knowledge and of truth
in so far as known."
Plato, Republic 508e.2–3
Plato, Republic 507b–509c
