From the Notebooks — Leonardo da Vinci

As a well-spent day brings happy sleep, so a life well used brings happy death. Iron rusts from disuse; stagnant water loses its purity and in cold freezes: even so does inaction sap the vigour of the

As a well-spent day brings happy sleep, so a life well used brings happy death. Iron rusts from disuse; stagnant water loses its purity and in cold freezes: even so does inaction sap the vigour of the mind. Learning never exhausts the mind. Nothing strengthens authority so much as silence. The noblest pleasure is the joy of understanding.

From the Notebooks — Leonardo da Vinci