Whoever would be obliged to obey a constitutional law, is justified in refusing to obey an unconstitutional act of the legislature.  When a question, even of this delicate nature, occurs, every one who is called to act, has a right to judge.

                                                       James Wilson

Cowardice asks the question:  Is it safe?

Expediency asks the question:  Is it politic?

Vanity asks the question:  Is it popular?

But conscience asks the question:  Is it right?

And there comes a time one must take a position that is neither safe, nor politic, nor popular -- but one must take it simply because it is right.

                                                Martin Luther King

It is not only [the juror's] right, but his duty . . . to find the verdict according to his own best understanding, judgment, and conscience, though in direct opposition of the court.

                                               John Adams

2 John Adam's Works 253-55 by Charles Francis Adams (Books for Libraries Press 1969) (1850-56).

When law and morality contradict each other, the citizen has the cruel alternative of either losing his moral sense or losing his respect for the law.

                                                           Frederic Bastiat

I consider trial by jury as the only anchor yet imagined by man by which a government can be held to the principles of its constitution.

                                                   Thomas Jefferson

Letter to Thomas Paine in 1789.  

THOMAS JEFFERSON, 7 THE WRITINGS OF THOMAS JEFFERSON 408 (Lipscomb and Bergh, ed., Memorial ed., 1903).