The speaker addresses someone absent or dead, a thing, a place, or an idea, as if they could hear.
In Notes from Underground
You believe in a crystal edifice, eternally unshakable, that is, one in which one could not even stick one's tongue out on the sly, nor make a fig in one's pocket.
The narrator addresses «you», the gentlemen who believe in progress, as if they were before him. This invented interlocutor, whom he provokes and contradicts, is the reader he imagines and despises, and the argument with him gives Part One the tone of someone who talks to himself and quarrels with an absent audience.