The silence that enfolds something kept unsaid points to the unsayable. By being wrapped in silence, what is arcane (kept hidden) comes to participate in what is esoteric (by its nature inexpressible). The secret becomes a symbol of the mystery, participating in what it points to, by the way in which it points to it.
A thing is not esoteric because it is secret or kept hidden. It is esoteric because its existence is in some sense unmanifest, private, and by its very nature not available for examination from the outside: it is only available to participation, not, ultimately, merely to examination. In other words, the realm of the esoteric is, before anything else, the realm of consciousness, of experience.