We admit, as all must admit, that the powers of the Government are limited, and that its limits are not to be transcended. But we think the sound construction of the Constitution must allow to the national legislature that discretion with respect to the means by which the powers it confers are to be carried into execution which will enable that body to perform the high duties assigned to it in the manner most beneficial to the people. Let the end be legitimate, let it be within the scope of the constitution, and all means which are appropriate, which are plainly adapted to that end, which are not prohibited, but consist with the letter and spirit of the constitution, are constitutional.

Courts are the mere instruments of the law, and can will nothing. When they are said to exercise a discretion, it is a mere legal discretion, a discretion to be exercised in discerning the course prescribed by law; and, when that is discerned, it is the duty of the Court to follow it. Judicial power is never exericised for the purpose of giving effect to the will of the Judge; always for the purpose of giving effect to the will of the Legislature; or, in other words, to the will of the law.

An unlimited power to tax involves, necessarily, a power to destroy; because there is a limit beyond which no institution and no property can bear taxation. A question of constitutional power can hardly be made to depend on a question of more or less. If the states may tax, they have no limit but their discretion; and the bank, therefore, must depend on the discretion of the state governments for its existence. This consequence is inevitable. The object in laying this tax, may have been revenue to the state. In the next case, the object may be to expel the bank from the state; but how is this object to be ascertained, or who is to judge of the motives of legislative acts?