"Transcendental" in this case is used as an adjective specifying a specific kind of argument, and not a noun. Transcendental arguments should not be confused with arguments for the existence of something
transcendent. Rather, transcendental arguments are arguments that make inferences from the ability to think and experience. So-called
progressive transcendental arguments begin with an apparently indubitable and universally accepted statement about people's experiences of the world. They use this to make substantive knowledge-claims about the world, e.g., that it
is causally and spatiotemporally related. They start with what is left at the
end of the skeptic's process of doubting. Progressive transcendental arguments take the form of
modus ponens with
modal operators: :If possibly
P, then necessarily
Q. :Actually
P. :Therefore, necessarily
Q.
Regressive transcendental arguments, on the other hand,
begin at the same point as the skeptic, e.g., the fact that we have experience of a causal and spatiotemporal world, and show that certain notions are implicit in our conceptions of such experience. Regressive transcendental arguments are more conservative in that they do not purport to make substantive ontological claims about the world. Regressive transcendental arguments take the form of
modus tollens with modal operators: :If possibly
P, then necessarily
Q. :Actually not
Q. :Therefore, necessarily not
P. They are also sometimes said to be distinct from standard
deductive and
inductive forms of
reasoning, although this has been disputed, for instance by Anthony Genova and Graham Bird. ==The argument==