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.

The faculty of imagination is both the rudder and the bridle of the senses.

Iron rusts from disuse; stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind.

Intellectual passion drives out sensuality.

I have offended God and mankind because my work did not reach the quality it should have.

Life well spent is.long.

I have from an early age abjured the use of meat, and the time will come when men such as I will look upon the murder of animals as they now look upon the murder of men.

Truly man is the king of beasts, for his brutality exceeds theirs. We live by the death of others: We are burial places!

Man and the animals are merely a passage and channel for food, a tomb for other animals, a haven for the dead, giving life by the death of others, a coffer full of corruption.

He turns not back who is bound to a star.