Malebranche, for example, is said to have heard the voice of God calling him.

Descartes says that, after a long confinement, he was followed by an invisible person, calling him to pursue his search for truth.

Dr.Johnson narrates that he once heard his absent mother calling him.

Byron tells us that he was sometimes visited by spectres.

Goethe records that he once saw an exact counterpart of himself coming towards him.