To learn without thinking is labour in vain, to think without learning is desolation.

There has never been a man mean and at the same time virtuous.

A blemish may be removed from a diamond by careful polishing, but evil words once spoken cannot be effaced.

Because the newer methods of treatment are good, it does not follow that the old ones were bad: for if our honorable and worshipful ancestors had not recovered from their ailments, you and I would not be here today.

What Heaven has conferred is called The Nature; an accordance with this nature is called The Path of duty; the regulation of this path is called Instruction. The path may not be left for an instant. If it could be left, it would not be the path.

To be wealthy and honored in an unjust society is a disgrace.

He who sling mud, lose ground.