Theages in Wikipedia
Theages is a dialogue attributed to Plato, featuring Demodocus, Socrates and Theages. There is debate over its authenticity; W. R. M. Lamb draws this conclusion from his opinion that the work is inferior and un-Socratic, but acknowledges that it was universally regarded as authentic in antiquity.
In the dialogue, Demodocus introduces his son Theages to Socrates for the first time, and they discuss Socrates' divine inner voice. Four separate cases are described in which Socrates received a premonition from the gods, but in each case the advice was ignored with disastrous consequences. Socrates is also presented as having a divine power which has a magical effect on his pupils, but which disappears when they abandon him to pursue other interests.
Theages 125e8-126a4 is quoted by Nietzsche in Will to Power §958: "In Plato's Theages it is written: 'Each one of us would like to be master over all men, if possible, and best of all God.' This attitude must exist again" (trans. Walter Kaufmann).