Philosophy was never anything but the mediation of the immediable: of reason to non-reason, of the finite to the infinite, of being to becoming, of the sayable to the unsayable, of knowledge to unknowing, etc. Wittgenstein’s theory of language-games and forms of life insists on the originary embeddedness of any knowledge in contexts that lack an ultimate basis in an absolute system of reference. Descartes bases certitudo on a fundamentum inconcussum, the ego cogito; Wittgenstein, by contrast, declares such a foundation to be inexistent. He does not deny that there is, that there can be knowledge; he shows that cognition and knowledge require a prosthetic faith and a trust that are “corroborated” by experience. Knowledge rests on a form of experiential knowing that engenders conventions as it relies on conventions. What Wittgenstein says ex negativo is that no knowledge is absolute. It owes its objectivity to the convention of the language-game, which for its part lacks ultimate foundation. Perhaps we may say of this convention that it is the glue of our realities. A minimum of agreement is the condition of the possibility of certainty, i.e., of reality. For what is reality if not the product of a convention that constitutes our knowledge? Hence the plural, the implicit we that indicates the community of believers in fact, the community of subjects that trusts in the solidity of its certainties without basing them on an absolute foundation: a community that confirms the inconsistency of its consistencies by acknowledging them to be precarious constructions. I call reality the aggregate of consistencies handed down by tradition, on which even the most recent and the most outlandish evidences rest. How to define an experience that convicts this aggregate of its arbitrariness, of its ontological contingency?