John Catron,
Hooper v. Scheimer — Opinion of the Court
“ In the case of an actual and perfect patent, there is no remedy but to set it aside in a court of equity, or in some direct proceeding having that for its direct end and object. It cannot be done in the ordinary progress of a trial at law, on evidence which the party had no means to know would be relied on, and therefore could not be prepared to meet. In other words, you cannot go behind a patent in a trial at law. The patent alone must prevail. ”
