If you are representing a white body let it be surrounded by ample space, because as white has no colour of its own, it is tinged and altered in some degree by the colour of the objects surrounding it

Truth is so excellent, that if it praises but small things they become noble.

Let proportion be found not only in numbers and measures, but also in sounds, weights, times, and positions, and what ever force there is.

If a man has a tent made of linen of which the apertures have all been stopped up, and be it twelve bracchia across (over twenty-five feet) and twelve in depth, he will be able to throw himself down from any height without sustaining injury. [His concept of the parachute.]

Given the cause nature produces the effect in the briefest manner that it can employ.

Details make perfection, and perfection is not a detail.

Knowledge ... shall always bear witness like a clarion to its creator.