In re Stephen W. Comiskey, 2007 (Software Patents)

In this case, the Federal Circuit held that methods that employ only human intelligence without involving machines, manufactures, or compositions of matter do not qualify as statutory suject matter under 35 U.S.C. Section 101 because they are directed to abstract ideas.

According to the Comiskey court, mental processes (or processes of human thinking) standing alone are not patentable even if they have a practical application.

The Court concluded that:

It is thus clear that the present statute does not allow patents to be issued on particular business systems—such as a particular type of arbitration—that depend entirely on the use of mental processes. In other words, the patent statute does not allow patents on particular systems that depend for their operation on human intelligence alone, a field of endeavor that both the framers and Congress intended to be beyond the reach of patentable subject matter. Thus, it is established that the application of human intelligence to the solution of practical problems is not in and of itself patentable.

The case can be found here: http://www.fedcir.gov/opinions/06-1286.pdf