A bird is an instrument working according to mathematical law, which instrument it is within the capacity of man to reproduce with all its movements, but not with a corresponding degree of strength, though it is deficient only in the power of maintaining equilibrium. We may therefore say that such an instrument constructed by man is lacking in nothing except the life of the bird, and this life must needs be supplied from that of man.
Leonardo da VinciYou don't get into trouble because of the things you don't know. It is the things you don't know you don't know that really get you into a mess.
Leonardo da VinciMen of genius sometimes accomplish most when they work least, for they are thinking out inventions.
Leonardo da VinciThere is no object so large but that at a great distance from the eye it does not appear smaller than a smaller object near.
Leonardo da Vinci