arising under

A suit for damages to business caused by a threat to sue under the patent law is not itself a suit under the patent law. And the same is true when the damage is caused by a statement of fact,—that the defendant has a patent which is infringed. What makes the defendants' act a wrong is its manifest tendency to injure the plaintiff's business; and the wrong is the same whatever the means by which it is accomplished. But whether it is a wrong or not depends upon the law of the state where the act is done, not upon the patent law, and therefore the suit arises under the law of the state. A suit arises under the law that creates the cause of action.