You are your oracle. Marcus Aurelius 2.13

Marcus advises himself to take counsel with his own spirit, rather than consult dead ancestors in the manner familiar to many ancient cultures (necromancy: cf. Odyssey 11, 1 Samuel 28, Aeneid 6). He sounds a little like Socrates, who told the Athenians that he received timely instruction from a spirit (δαίμων) unique to himself (Plato, Apology 31d). <Greek>.

Οὐδὲν ἀθλιώτερον τοῦ πάντα κύκλῳ ἐκπεριερχομένου καὶ «τὰ νέρθεν γᾶς» φησὶν «ἐρευνῶντος» καὶ τὰ ἐν ταῖς ψυχαῖς τῶν πλησίον διὰ τεκμάρσεως ζητοῦντος, μὴ αἰσθομένου δέ, ὅτι ἀρκεῖ πρὸς μόνῳ τῷ ἔνδον ἑαυτοῦ δαίμονι εἶναι καὶ τοῦτον γνησίως θεραπεύειν. θεραπεία δὲ αὐτοῦ, καθαρὸν πάθους διατηρεῖν καὶ εἰκαιότητος καὶ δυσαρεστήσεως τῆς πρὸς τὰ ἐκ θεῶν καὶ ἀνθρώπων γινόμενα. τὰ μὲν γὰρ ἐκ θεῶν αἰδέσιμα δι' ἀρετήν· τὰ δὲ ἐξ ἀνθρώπων φίλα διὰ συγγένειαν, ἔστι δὲ ὅτε καὶ τρόπον τινὰ ἐλεεινὰ δι' ἄγνοιαν ἀγαθῶν καὶ κακῶν· οὐκ ἐλάττων ἡ πήρωσις αὕτη τῆς στερισκούσης τοῦ διακρίνειν τὰ λευκὰ καὶ μέλανα.

Nothing worse than going about ever in circles, “chasing what lies underground” as the saying goes, seeking signs from familiar spirits, failing to notice that it is enough to rely upon the spirit in your own breast, and serve it faithfully. Serving it means keeping it clean, unspoilt by passion, thoughtlessness, or distress arising from the deeds of gods and men. What the gods do commands respect because of its excellence. What men do is near and dear to us because of our kinship with them, though they move us to pity sometimes, when they act in ignorance of good and evil. Such ignorance is an affliction no less severe than the one that removes our ability to distinguish black and white.