All life is problem solving.

Unlimited tolerance must lead to the disappearance of tolerance.

A theory which is not refutable by any conceivable event is non-scientific.

You must learn all things: both the steadfast heart of well-rounded Truth and the opinions of mortals, in which there is no true trust.

-- Parmenides

For thinking and Being are the same.

-- Parmenides

Color exists by convention, sweet by convention, bitter by convention; in reality there are only atoms and void.

-- Democritus

I know that I know nothing.

-- Socrates

I know that I do not know.

-- Plato

Imagine prisoners chained underground since childhood, seeing only shadows on a wall and taking them for reality.

-- Plato