The gifts given to us by God must not be relinquished to those who speak ill of them and who are moved by envy or ignorance.

Do not share your inventions with many; share them only with the few who understand and love the sciences.

We must not show to all and sundry the secrets of the waters flowing in ocean and river, or the devices that work on these waters. Let there be convened a council of experts and masters in mechanical art to deliberate what is needed to compose and construct these works.

Envy comes from people's ignorance of, or lack of belief in, their own gifts

To disclose too much of one's inventions and achievements is one and the same thing as to give up the fruit of one's ingenuity.

I propose to build for eternity.