The first and primary axiomatic concepts are “existence,” “identity” (which is
a corollary of “existence”) and “consciousness.” One can study what exists and
how consciousness functions; but one cannot analyze (or “prove”) existence as
such, or consciousness as such. These are irreducible primaries. (An attempt to
“prove” them is self-contradictory: it is an attempt to “prove” existence by
means of non-existence, and consciousness by means of unconsciousness.)