For the power given to Congress by the Constitution does not extend to the internal regulation of the commerce of a State (that is to say, of the commerce between citizen and citizen,) which remain exclusively with its own legislature; but to its external commerce only, that is to say, its commerce with another State, or with foreign nations, or with the Indian tribes.

I hold it certain that to open the doors of truth and to fortify the habit of testing everything by reason are the most effectual manacles we can rivet on the hands of our successors to prevent their manacling the people with their own consent.

How much pain they have cost us, the evils which have never happened.

The sun - my almighty physician.

We never repent of having eaten too little.

All through your life, you'll be faced with making a decision between two things-choose the one that is right. If they are both right, then choose the one that will make you feel the best about it at the end of the day.

Idleness begets ennui, ennui the hypochondriac, and that a diseased body. No laborious person was ever yet hysterical.