A well-spent day brings happy sleep.
Leonardo da Vinci

All our knowledge has its origins in our perceptions.
Leonardo da Vinci

Although nature commences with reason and ends in experience it is necessary for us to do the opposite, that is to commence with experience and from this to proceed to investigate the reason.
Leonardo da Vinci

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.
Leonardo da Vinci

Art is never finished, only abandoned.
Leonardo da Vinci

As a well-spent day brings happy sleep, so a life well spent brings happy death.
Leonardo da Vinci

As every divided kingdom falls, so every mind divided between many studies confounds and saps itself.
Leonardo da Vinci

Beyond a doubt truth bears the same relation to falsehood as light to darkness.
Leonardo da Vinci

Blinding ignorance does mislead us. O! Wretched mortals, open your eyes!
Leonardo da Vinci

Common Sense is that which judges the things given to it by other senses.
Leonardo da Vinci


Experience does not err. Only your judgments err by expecting from her what is not in her power.
Leonardo da Vinci

For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return.
Leonardo da Vinci

He who is fixed to a star does not change his mind.
Leonardo da Vinci

He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never knows where he may cast.
Leonardo da Vinci

He who wishes to be rich in a day will be hanged in a year.
Leonardo da Vinci

Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.
Leonardo da Vinci

I have been impressed with the urgency of doing. Knowing is not enough; we must apply. Being willing is not enough; we must do.
Leonardo da Vinci

I have offended God and mankind because my work didn't reach the quality it should have.
Leonardo da Vinci

I have wasted my hours.
Leonardo da Vinci

I love those who can smile in trouble, who can gather strength from distress, and grow brave by reflection. 'Tis the business of little minds to shrink, but they whose heart is firm, and whose conscience approves their conduct, will pursue their principles unto death.
Leonardo da Vinci