The primary axiom, which is the foundation of all other axioms, is our own existence, and although this cannot be tested in a laboratory, there is not a single person on earth who is capable of denying or escaping the basic truth that he exists. Certainly, no one is willing to die based on this assumption. Moreover, the awareness of existing is far greater and more powerful than any other experience. The very fact that we are aware and experience anything, is proof positive that we exist, for otherwise, who is experiencing? We, therefore, accept our existence as axiomatic in everything we do, for if we actually believed we did not exist, and operated under that assumption, we would be incapable of doing anything. We could not eat, drink, move or even breathe. A nonexistent being does not breathe. The very fact that all people breathe, proves, without a doubt, that they believe they exist.
Because it is universally accepted that we exist (as evidenced by the fact that everyone eats, drinks, moves and breathes etc.) we may establish this as an incontrovertible and self evident truth. We will, therefore, use our existence as the primary axiom in determining the true path to G-d. (Anyone who seriously disputes this may demonstrate his convictions by jumping off a bridge with total indifference to his life.) We may, therefore, test the claims of all paths and religions against the axiom. (True Kabbalah.com)
