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.

Good fortune is the greatest of blessings, but good counsel comes next, and the lack of it destroys the other also.

The sower of the seed is assuredly the author of the whole harvest of mischief.

A man is his own easiest dupe, for what he wishes to be true he generally believes to be true.

Since we are not yet fully comfortable with the idea that people from the next village are as human as ourselves, it is presumptuous in the extreme to suppose we could ever look at sociable, tool-making creatures who are from other evolutionary paths and see not beasts, but brothers, not rivals, but fellow pilgrims journeying to the shrine of intelligence...The difference... is not in the creature judged, but in the creature judging.

It is impossible for men engaged in low and groveling pursuits to have noble and generous sentiments. A man's thought must always follow his employment.

Every dictator is an enemy of freedom, an opponent of law.