The principle of Identity

I will keep on talking about the First Principles. I will talk about the principle of  identity. A thing must be identical to itself. If it were not, then it would not be itself.
While these and other principles, it is important to note the difference between unsayable and undeniable. I can say or write the words, "I do not exist." However, when I said it I implicitly affirmed that I do exist. The affirmation that I do not exist is actually unaffirmable. I must actually exist in order to grammatically say I do not exist.