First, let's check the dictionary: "Petty juries, consisting usually of twelve men, attend courts to try matters of fact in civil causes, and to decide both the law and the fact in criminal prosecutions. The decision of a petty jury is called a verdict."
— Noah Webster, Dictionary of the English Language, 1828
"It is left... to the juries, if they think the permanent judges are under any bias whatever in any cause, to take on themselves to judge the law as well as the fact. They never exercise this power but when they suspect partiality in the judges; and by the exercise of this power they have been the firmest bulwarks of English liberty."
— Thomas Jefferson to Abbe Arnoux; 1789. ME 7:423, Papers 15:283
"If the question before [the magistrates] be a question of law only, they decide on it themselves: but if it be of fact, or of fact and law combined, it must be referred to a jury. In the latter case of a combination of law and fact, it is usual for the jurors to decide the fact and to refer the law arising on it to the decision of the judges. But this division of the subject lies with their discretion only. And if the question relate to any point of public liberty, or if it be one of those in which the judges may be suspected of bias, the jury undertake to decide both law and fact. If they be mistaken, a decision against right which is casual only is less dangerous to the state and less afflicting to the loser than one which makes part of a regular and uniform system."
— Thomas Jefferson: Notes on Virginia Q.XIV, 1782. ME 2:179
"The juries [are] our judges of all fact, and of law when they choose it."
— Thomas Jefferson to Samuel Kercheval; 1816. ME 15:35
"We all know that permanent judges acquire an esprit de corps; that, being known, they are liable to be tempted by bribery; that they are misled by favor, by relationship, by a spirit of party, by a devotion to the executive or legislative; that it is better to leave a cause to the decision of cross and pile* than to that of a judge biased to one side; and that the opinion of twelve honest jurymen gives still a better hope of right than cross and pile does."
— Thomas Jefferson to Abbe Arnoux; 1789. ME 7:423, Papers 15:283
Cross and Pile meant
heads or tails or a coin toss
".....it is usual for the jurors to decide the fact, and to refer the law arising on it to the decision of the judges. But this division of the subject lies with their discretion only. And if the question relate to any point of public liberty, or if it be one of those in which the judges may be suspected of bias, the jury undertake to decide both law and fact.
— Thomas Jefferson,
Notes on Virginia, 1782
"I consider trial by jury as the only anchor yet devised by man, by which a government can be held to the principles of its constitution."
— Thomas Jefferson, in a letter to Thomas Paine; 1789
"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 to the direction of the court."
— John Adams , America's second President; 1771
"It would be an absurdity for jurors to be required to accept the judge's view of the law, against their own opinion, judgment, and conscience."
— John Adams
It is presumed, that juries are the best judges of facts; it is, on the other hand, presumed that courts are the best judges of law. But still both objects are within your power of decision.....you have a right to take it upon yourselves to judge of both, and to determine the law as well as the fact in controversy.
— Chief Justice John Jay, Georgia v. Brailsford, 1794
"The jury has the right to judge both the law as well as the fact in controversy."
— John Jay, the first Chief Justice of the U. S. Supreme Court; 1789
"The jury has the right to determine both the law and the facts."
— Samuel Chase, U. S. Supreme Court Justice and signer of the Declaration of Independence; 1796
"Jurors should acquit, even against the judge's instruction... if exercising their judgment with discretion and honesty, they have a clear conviction the charge of the court is wrong."
— Alexander Hamilton, 1804
"The jury has the power to bring a verdict in the teeth of both law and fact."
— Oliver Wendell Holmes ;U. S. Supreme Court Justice; 1902
"The jury has the power to bring a verdict in the teeth of both the law and the facts. "
— Justice Oliver Wendell Holmes, Horning v. District of Columbia, 1920
"The law itself is on trial, quite as much as the cause which is to be decided."
— Harlan F. Stone, the 12th Chief Justice of the U. S. Supreme Court; 1941
Consider U.S. Chief Justice Harlan F. Stone on the Juror's Duty, as follows:
"If a juror feels that the statute involved in any criminal offence is unfair, or that it infringes upon the defendant's natural God-given unalienable or Constitutional rights, then it is his duty to affirm that the offending statute is really no law at all and that the violation of it is no crime at all, for no one is bound to obey an unjust law."
"That juror must vote Not Guilty regardless of the pressures or abuses that may be heaped on him by any or all members of the jury with whom he may in good conscience disagree. He is voting on the justice of the law according to his own conscience and convictions and not someone else's. The law itself is on trial quite as much as the case which is to be decided."
— U.S. Chief Justice Harlan F. Stone, 1941-1946.
It is universally conceded that a verdict of acquittal, although rendered against the instructions of the judge, is final, and cannot be set aside; and consequently that the jury have the legal power to decide for themselves the law involved in the general issues of guilty or not guilty.
— Justices Gray and Shiras, Sparf and Hansen v. United States, 1894, dissent
If the jury feels the law is unjust, we recognize the undisputed power of the jury to acquit, even if its verdict is contrary to the law as given by a judge, and contrary to the evidence...If the jury feels that the law under which the defendant is accused is unjust, or that exigent circumstances justified the actions of the accused, or for any reason which appeals to their logic or passion, the jury has the power to acquit, and the courts must abide by that decision.
— 4th Circuit Court of Appeals, United States v. Moylan, 1969
[The jury has an] unreviewable and irreversible power...to acquit in disregard of the instructions on the law given by the trial judge...The pages of history shine on instances of the jury's exercise of its prerogative to disregard uncontradicted evidence and instructions of the judge; for example, acquittals under the fugitive slave law.
— D.C. Circuit Court of Appeals, Unites States v. Dougherty, 1972
"The pages of history shine on instances of the jury's exercise of its prerogative to disregard instructions of the judge."
— U. S. v Dougherty, 473 F 2nd 1113, 1139, the U.S. Supreme Court; 1972
JUSTICE HUGO BLACK, (Assoc. Justice U.S. Supreme Court, 1937-1971) a great believer in the Jury system, used to tell this story:
Years ago, in the foot-hills of Alabama, a tenant-farmer was charged criminally with stealing a cow from his landlord, and was brought to trial. As was frequently the case in rural America, the Jurors selected for the trial were acquainted with everyone, including the accused and his victim. Each juror knew that the farm's landlord was a nasty bastard who tormented his neighbors, while frequently treating the town's orphans and widows with derision. By the same token, the tenant-farmer was the salt of the earth, beloved by everyone. But still, the evidence of his guilt was indisputable.
After the evidence was in and the jury retired to deliberate, it quickly returned to the courtroom to announce its verdict: "If the accused returns the cow, we find him not guilty."
The judge was infuriated. His anger heightening, he commanded the jury to return to the jury room to deliberate --shrilly chastising them for their flagrantly "arrogant" and "illegal" verdict.
Not a moment passed when they re-appeared in the tense courtroom to trumpet their new verdict: "We find the accused not guilty -- and he can keep the cow."
The American Jury, Justice Black reminds his listeners, is effectively omnipotent in rendering an acquittal. What hits home in Justice Black's story is the deeply-held American notion that juries often perform an independent role in a system in which the people - not prosecutors, judges or lawyers - have the last word. In the end, if the jury wishes to let the defendant keep the cow, that is what will happen.
Charles Kenyon, Assistant State Public Defender Marinette, Wisconsin, quotes Winston Churchill's A HISTORY OF THE ENGLISH SPEAKING PEOPLE regarding King Henry II in the twelfth century:
"The jury system has come to stand for all we mean by English justice, because so long as a case has to be scrutinized by twelve honest men, defendant and plaintiff alike have a safe-guard from arbitrary perversion of the law. It is this which distinguishes the law administered in English courts from Continental legal systems based on Roman law. Thus amidst the great process of centralization the old principle was preserved, and endures to this day, that law flows from the people, and is not given by the King."
— [Vol.I, p.219]...
"Even the framers of the Magna Carta did not attempt to lay down new law or proclaim any broad general principles. This was because both sovereign and subject were in practice bound by the Common Law, and the liberties of Englishmen rested not in any enactment of the State, but on immemorial slow-growing custom declared by juries of free men who gave their verdicts case by case in open court."
— [Vol. I,p.225]
In the trial of all criminal cases, the Jury shall be the Judges of Law, as well as of fact, except that the Court may pass upon the sufficiency of the evidence to sustain a conviction
— Article XXIII, Constitution of the State of Maryland
In all criminal cases whatsoever, the jury shall have the right to determine the law and the facts.
— Article I, §19, Constitution of the State of Indiana
Lysander Spooner, An Essay on the Trail by Jury, 1852:
The question here arises, Whether the barons and the people intended that those peers (the jury) should be mere puppets in the hands of the king, exercising no opinion of their own as to the intrinsic merits of the accusations they should try, or the justice of the laws they should be called on to enforce? Whether those haughty and victorious barons, when they had their tyrant king at their feet, gave back to him his throne, with full power to enact any tyrannical laws he might please, reserving only to a jury...the contemptible and servile privilege of ascertaining, (under the dictation of the king, or his judges, as to the laws of evidence), the simple fact whether those laws had been transgressed? Was this the only restraint, which, when they had all power in their hands, they placed upon the tyranny of a king, whose oppressions they had risen in arms to resist? Was it to obtain such a charter as that, that the whole nation had united, as it were, like one man, against their king? Was it on such a charter that they intended to rely, for all future time, for the security of their liberties? No. They were engaged in no such senseless work as that. On the contrary, when they required him to renounce forever the power to punish any freeman, unless by the consent of his peers, they intended those peers should judge of, and try, the whole case on its merits, independently of all arbitrary legislation, or judicial authority, on the part of the king. In this way they took the liberties of each individual--and thus the liberties of the whole people--entirely out of the hands of the king, and out of the power of his laws, and placed them in the keeping of the people themselves. And this it was that made the trial by jury the palladium of their liberties.
The trial by jury, be it observed, was the only real barrier interposed by them against absolute despotism. Could this trial, then, have been such an entire farce as it necessarily must have been, if the jury had had no power to judge of the justice of the laws the people were required to obey? Did it not rather imply that the jury were to judge independently and fearlessly as to everything involved in the charge, and especially as to its intrinsic justice, and thereon give their decision, (unbiased by any legislation of the king,) whether the accused might be punished? The reason of the thing, no less than the historical celebrity of the events, as securing the liberties of the people, and the veneration with which the trail by jury has continued to be regarded, notwithstanding its essence and vitality have been almost entirely extracted from it in practice, would settle the question, if other evidences had left the matter in doubt.
"Where powers are assumed which have not been delegated, a nullification of the act is the rightful remedy."
— Thomas Jefferson: Kentucky Resolutions, 1798