The question is:

How should skepticism refer to itself?

The classical example might be the doubt of Descartes, which led him to the necessary obviousness of who doubts. The formal logical structure is the same as the “antinomy of the Liar”. That new interpretation of it can be called “antinomy of the Skeptic”. Descartes resolved it by introducing the meta-position and furthermore defining the “Self” just as that meta-position allows of any other position including that of doubt.

Rather unexpectedly, one can reveal the sceptic position to itself in Heisenberg’s uncertainty in quantum mechanics. It generates the necessity of the observer in final analysis as what allows of that fundamental principle of uncertainty. As the Self of Descartes, the observer in quantum mechanics is necessary logically for one to be able to state certainly the uncertainly of all, which is not the observer.