Between knowledge of what really exists and ignorance of what does not exist lies the domain of opinion. It is more obscure than knowledge, but clearer than ignorance.

The greatest mistake in the treatment of diseases is that there are physicians for the body and physicians for the soul, although the two cannot be separated.

My plainness of speech makes people hate me, and what is their hatred but a proof that I am speaking the truth.

The beginning is half of the whole.

We understand why children are afraid of darkness ... but why are men afraid of light?

The most beautiful motion is that which accomplishes the greatest results with the least amount of effort.

There is far greater peril in buying knowledge than in buying meat and drink.