But rights must be contested in order to warrant the interference of a tribunal; and an action must be brought to obtain the decision of a judge.

As long, therefore, as the law is uncontested, the judicial authority is not called upon to discuss it, and it may exist without being perceived.

When a judge in a given case attacks a law relating to that case, he extends the circle of his customary duties, without however stepping beyond it; since he is in some measure obliged to decide upon the law in order to decide the case.

But if he pronounces upon a law without resting upon a case, he clearly steps beyond his sphere, and invades that of the legislative authority.
The second characteristic of judicial power is that it pronounces on special cases, and not upon general principles.

If a judge in deciding a particular point destroys a general principle, by passing a judgment which tends to reject all the inferences from that principle, and consequently to annul it, he remains within the ordinary limits of his functions.