Just as eating against one’s will is injurious to health, so studying without a liking for it spoils the memory, and it retains nothing it takes in. - Leonardo da Vinci

Study without desire spoils the memory, and it retains nothing that it takes in.

The abbreviators of works do injury to knowledge and to love.Of what value is he who,in order to abbreviate the parts of those things of which he professes to give complete knowledge,leaves out the greater part of the things of which the whole is composed?Oh human stupidity!You don’t see that you are falling into the same error as one who strips a tree of its adornment of branches full of leaves,intermingled with fragrant flowers or fruit in order to demonstrate that the tree is good for making planks

Fine gold is recognized when it is tested.

Quelli che s’innamorano della pratica senza la scienza, sono come i nocchieri che entrano in naviglio senza timone o bussola, che mai hanno certezza dove si vadano. Sempre la pratica dev’essere edificata sopra la buona teorica, della quale la prospettiva è guida e porta, e senza questa nulla si fa bene.