Nature is so delightful and abundant in its variations that among trees of the same kind there would not be found one which nearly resembles another, and not only the plants as a whole, but among their branches, leaves, and fruit, will not be found one which is precisely like another.
Leonardo da VinciThe earth is moved from its position by the weight of a tiny bird resting upon it.
Leonardo da VinciEvery now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer.
Leonardo da VinciAll our knowledge hast its origins in our perceptions … In nature there is no effect without a cause … Experience never errs; it is only your judgments that err by promising themselves effects such as are not caused by your experiments … Science is the observation of things possible, whether present or past; prescience is the knowledge of things which may come to pass.
Leonardo da Vinci