Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.Leonardo da Vinci
To such an extent does nature delight and abound in variety that among her trees there is not one plant to be found which is exactly like another; and not only among the plants, but among the boughs, the leaves and the fruits, you will not find one which is exactly similar to another.Leonardo da Vinci
Man and animals are in reality vehicles and conduits of food, tombs of animals, hostels of Death, coverings that consume, deriving life by the death of others.Leonardo da Vinci
Weight, force and casual impulse, together with resistance, are the four external powers in which all the visible actions of mortals have their being and their end.Leonardo da Vinci
Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.Leonardo da Vinci
Necessity is the mistress and guide of nature. Necessity is the theme and inventress of nature, her curb and her eternal law.Leonardo da Vinci
Dear God! how beauty varies in nature and art. In a woman the flesh must be like marble; in a statue the marble must be like flesh.Victor Hugo
