The more necessary a thing is for living beings, the more easily it is found and the cheaper it is; the less necessary it is, the rarer and dearer it is.

For the elements have the property of moving back to their place in a straight line, but they have no properties which would cause them to remain where they are, or to move otherwise than in a straight line. The rectilinear motions of these four elements when returning to their original place are of two kinds, either centrifugal, viz., the motion of the air and the fire; or centripedal, viz., the motion of the earth, and the water; and when the elements have reached their original place, they remain at rest.

Astrology is a disease, not a science... It is a tree under the shadow of which all sorts of superstitions thrive. ... Only fools and charlatans lend value to it.

The third class of evils comprise those which everyone causes to himself by his own action. This is the largest class, and is far more numerous than the second class. It is especially of these evils that all men complain, - only few men are found that do not sin against themselves by this kind of evil. ...This class of evil originates in man's vices, such as excessive desire for eating, drinking, and love; indulgence in these things in undue measure, or in improper manner, or partaking of bad food. This course brings diseases and afflictions upon the body and soul alike.

God is identical with His attributes, so that it may be said that He is the knowledge, the knower, and the known.

The business conduct of the disciples of wise men is truthful and faithful.... He does not allow himself to be made a surety or a guarantor and does not accept the power of attorney.... He lends money and is gracious. He shall not take away business from his fellow man.

To sum up: I am the man who when the concern pressed him and his way was straitened and he could find no other device by which to teach a demonstrable truth other than by giving satisfaction to a single virtuous man while displeasing ten thousand ignoramuses - I am he who prefers to address that single man by himself, and I do not heed the blame of those many creatures.