Those who, in debate, appeal to their qualifications, argue from memory, not from understanding.

Marriage is like putting your hand into a bag of snakes in the hope of pulling out an eel.

A clever man without wisdom is like a beautiful flower without fragrance.

Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer. Go some distance away because then the work appears smaller and more of it can be taken in at a glance and a lack of harmony and proportion is more readily seen.

The eye transmits its own image through the air to all the objects which face it, and also receives them on its own surface, whence the "sensus communis" takes them and considers them.

Many will think they may reasonably blame me by alleging that my proofs are opposed to the authority of certain men held in the highest reverence by their inexperienced judgments; not considering that my works are the issue of pure and simple experience.

There are many kinds of beauty as people who possess it.