Some promises and time disappoint us

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.

The color of the object illuminated partakes of the color of that which illuminates it.

There is no result in nature without a cause; understand the cause and you will have no need of the experiment.

I am not poor. Poor are those who desire many things.

The merit of painting lies in the exactness of reproduction. Painting is a science and all sciences are based on mathematics. No human inquiry can be a science unless it pursues its path through mathematical exposition and demonstration.

Learning is the only thing the mind never exhausts, never fears, and never regrets.