A wave is never found alone, but is mingled with as many other waves as there are uneven places in the object where the said wave is produced.
Leonardo da VinciOh! Speculators on things, boast not of knowing the things that nature ordinarily brings about; but rejoice if you know the end of those things which you yourself device.
Leonardo da VinciPeople reveal themselves completely only when they are thrown out of the customary conditions of their life.
Leonardo da VinciThe painter will produce pictures of little merit if he takes the works of others as his standard.
Leonardo da Vinci