I am not poor. Poor are those who desire many things.

It had long since come to my attention that people of accomplishment rarely sat back and let things happen to them. They went out and happened to things.

I am never weary of being useful... In serving others I cannot do enough. No labor is sufficient to tire me.

A day will come in which men will look upon an animal's murder the same way they look today upon a man's murder.

The first of all simple colours is White ... We shall set down White for the representative of light, without which no colour can be seen; Yellow for the earth; Green for water; Blue for air; Red for fire; and Black for total darkness.

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.

O speculators about perpetual motion, how many vain chimeras have you created in the like quest? Go and take your place with the seekers after gold.