Sharks do not have a single bone in their bodies. Instead they have a skeleton made up of cartilage; the same type of tough, flexible tissue that makes up human ears and noses.

"Drawing is based upon perspective, which is nothing else than a thorough knowledge of the function of the eye."

"For example" is not proof.

"For millions of years, mankind lived just like the animals. Then something happened which unleashed the power of our imagination. We learned to talk and we learned to listen."

"Good culture is born of a good disposition; and since the cause is more to be praised than the effect, I will rather praise a good disposition without culture, than good culture without the disposition."