Ambition is a vice, but it may be the father of virtue

The mind is exercised by the variety and multiplicity of the subject matter, while the character is moulded by the contemplation of virtue and vice.

A liar should have a good memory

Virtue practiced to be seen is not real virtue; vice which fears to be seen is real vice

Virtue by calculation is the virtue of vice

Though ambition in itself is a vice, it often is also the parent of virtue.