Leonardo da Vinci

Just as food eaten without appetite is a tedious nourishment, so does study without zeal damage the memory by not assimilating what it absorbs.

Not to punish evil is equivalent to authorizing it.

The noblest pleasure is the joy of understanding.

Experience never errs; it is only your judgments that err by promising themselves effects such as are not caused by your experiments.

A feeble body weakens the mind.

In solitude, the mind gains strength and learns to lean upon itself.

He who wishes to be rich within a day, will be hanged within a year.

Learn how to see. Realize that everything connects to everything else.

Errors are not in the art but in the artificers.

Learning is the only thing the mind never exhausts, never fears, and never regrets.

Once you have tasted the taste of sky, you will forever look up.

One can have no smaller or greater mastery than mastery of oneself.

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

There are three classes of people: those who see. Those who see when they are shown. Those who do not see.

Just as a well-filled day brings blessed sleep, so a well-employed life brings blessed death.

Learning never exhausts the mind.

Simplicity is the ultimate sophistication.

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