Experience never misleads; what you are misled by is only your judgment, and this misleads you by anticipating results from experience of a kind that is not produced by your experiments.

Instrumental or mechanical science is the noblest and above all others, the most useful.

The worst evil which can befall the artist is that his work should appear good in his own eyes.

He who walks straight rarely falls.

To speak of this subject you must... explain the nature of the resistance of the air, in the second the anatomy of the bird and its wings, in the third the method of working the wings in their various movements, in the fourth the power of the wings and the tail when the wings are not being moved and when the wind is favourable to serve as guide in various movements.

The Medici made me and the Medici destroyed me.

Not to anticipate is already to moan.