A new scientific truth does not triumph by convincing its opponents, but rather because its opponents eventually die and a new generation grows up familiar with it.

An experiment is a question which science poses to Nature, and a measurement is the recording of Nature's answer.

No sign is so clear that it does not also carry some obscurity

-- John Calvin

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

I know that I know nothing.

-- Socrates

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

-- Plato

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

-- Democritus