Ataraxia in the face of desire, as an amplifier of desire, or its opposite a sort of complete shattering surrender, are hyperboles of the desiring self, images of rare transcendence by which we can measure the failures by which we are insistently and inescapably ourselves. Certainty and insistence can also be distinguished as mental modes that simulate a self, by being, as it were, constants outside the system of the contents. Certainty, whether necessary or contingent hardly matters, is the notion attached to certain beliefs that they are true in any possible world, and so its burden is ultimately just this 'any possible world', a contentless and infinite reference. Certainty, arising as a feeling, is what makes such a reference to infinity possible, like the calls on God in the throws of desire. Insistence is a related but different thing, it is the quality of absolute particularity, a sort of equivalent to solipsism. It might be the ground of egoism - the practical belief in being an exception to every generality. Yes, we are all human and so morally equivalent, but I am the only one I can be sure exists. This insistent existence is incredibly insecure just because it is so formally undoubtable. In reality I am always at risk of being substituted in any or all of my relationships and I look for assurances that will abolish this scandalous omission on the side of being.