Further, not only did we not rely on a "physical steps" test in Comiskey, but we
have criticized such an approach to the § 101 analysis in earlier decisions. In AT&T, we
rejected a "physical limitations" test and noted that "the mere fact that a claimed
invention involves inputting numbers, calculating numbers, outputting numbers, and
storing numbers, in and of itself, would not render it nonstatutory subject matter." 172
F.3d at 1359 (quoting State St., 149 F.3d at 1374). The same reasoning applies when
the claim at issue recites fundamental principles other than mathematical algorithms.
Thus, the proper inquiry under § 101 is not whether the process claim recites sufficient
"physical steps," but rather whether the claim meets the machine-or-transformation
test.
As a result, even a claim that recites "physical steps" but neither recites a
particular machine or apparatus, nor transforms any article into a different state or thing,
is not drawn to patent-eligible subject matter. Conversely, a claim that purportedly lacks
any "physical steps" but is still tied to a machine or achieves an eligible transformation
passes muster under § 101.
B.
With these preliminary issues resolved, we now turn to how our case law
elaborates on the § 101 analysis set forth by the Supreme Court. To the extent that
some of the reasoning in these decisions relied on considerations or tests, such as
"useful, concrete and tangible result," that are no longer valid as explained above, those
aspects of the decisions should no longer be relied on. Thus, we reexamine the facts of
25
Thus, it is simply inapposite to the § 101 analysis whether process steps
performed by software on a computer are sufficiently "physical."
26
Of course, a claimed process wherein all of the process steps may be
performed entirely in the human mind is obviously not tied to any machine and does not
transform any article into a different state or thing. As a result, it would not be patent-
eligible under § 101.
2007-1130 23