The Constitution imposes restrictions on the States, which of course means restrictions on their legislatures, their governors, and their courts. Upon principles of good government the States are prohibited from doing many things. How shall infractions of the supreme law be determined? Either by a congressional negative, or by the authority of the federal courts overruling whatsoever act of the State contravenes the Constitution.[250] 100. But the judicial power of the United States extends yet further,—to controversies “in which the State tribunals cannot be supposed to be impartial and unbiased.”[251] The principle here is that the whole is greater than a part; that the peace of the whole ought not to be left at the disposal of a part. “No man ought to be a judge in his own cause, or in any cause in respect to which he has the least interest or bias.”[252] On the principle that every government ought to possess the means of executing its own provisions by its own authority, it follows that it is necessary that the construction of the Constitution,—the supreme law,— should be committed to that tribunal which, having no local attachments, will be likely to be impartial between different States and their citizens, and which, owing its official existence to the Union, will never be likely to feel any bias inauspicious to the principles on which it is founded.[253] 101. The exercise of judicial power by the Supreme Court is provided for, in part, by the Constitution, but Congress is authorized to ordain and establish inferior courts,—which means to define their respective jurisdictions; to bestow upon a court so much judicial power, and to make such restrictions, rules, and regulations as Congress itself may deem proper. Thus Congress establishes such courts and defines their several jurisdictions, but whatsoever judicial power a court possesses, by act of Congress, the court derives from the Constitution in its grant of such power. The jurisdiction of any inferior court of the United States, thus defined by Congress, may vary, from time to time, by act of Congress, but every case arising in the court must be shown, by the record of the court, to be within its jurisdiction.[254] The reason for this important rule (and seeming restriction) conforms to the essential principle in all judicial proceeding: the principle of authority. No court acts without authority and, as judicial examination has for its ultimate purpose the settlement of controversy in a legal manner, the jurisdiction of the court is of primary importance. One of the purposes of the Union is “to establish justice,” and precision in the whole matter of exercise of judicial power is essential.