"There are all kinds of devices invented for the protection and
preservation of countries: defensive barriers, forts, trenches,
and the like... But prudent minds have as a natural gift one safeguard
which is the common possession of all, and this applies especially
to the dealings of democracies. What is this safeguard? Skepticism.
This you must preserve. This you must retain. If you can keep this,
you need fear no harm."