Guarding Thoughts

Τὰ νοήματα τοῦ αἰῶνος τούτου ὁ Κύριος καθάπερ πρόβατά τινα τῷ ἀγαθῷ ποιμένι τῷ ἀνθρώπῳ παρέδωκε· ̧ Κὰι γὰρ, φησί, σὺν τὸν αἰῶνα ἔδωκεν ἐν καρδίᾳ ἀυτοῦ,  συζεύξας αὐτῷ θυμὸν κὰι επιθυμίαν πρὸς βοήθειαν, ἵνα, διὰ μὲν τοῦ θυμου, φευγαδεύῃ τὰ τῶν λύκων νοήματα, διὰ δε τῆς ἐπιθυμίας στέργῃ τὰ πρόβατα, καὶ ὑπὸ τῶν ὑετῶν καὶ ἀνέμων πολλάκις βαλλόμενος· ἔδωκε πρὸς τούτοις καὶ νομὸν, ὅπως ποιμαίνῃ τὰ πρόβατα, καὶ τόπον χλόης, καὶ ὕδωρ ἀναπαύσεως καὶ ψαλτήριον καὶ κιθάραν καὶ ῥάβδον καὶ βακτηρίαν, ἵν' ἐκ ταύτης τῆς ποίμνης καὶ τραφῇ καὶ ἐνδύσηται καὶ χόρτον ὀρεινὸν συναγάγῃ· Τίς γὰρ, φησὶ, ποιμαίνει ποίμνην, καὶ ἐκ τοῦ γάλακτος τῆς ποίμνης οὐκ ἐσθίεις; Δεῖ οὖν τὸν ἀναχωροῦντα φυλάττειν νύκτωρ, καὶ μεθ´ ἡμέραν τοῦτο τὸ ποίμνιον, μήτι τῶν νοημάτων γένηται θηριάλωτον, ἢ λῃσταῖς περιπέσῃ, εἰ δὲ ἄρα τι τοιοῦτο συμβαίη κατὰ τὴν νάπην, εὐθέως ἐξαρπάζειν ἐκ τοῦ στόματος τοῦ λέοντος ἢ τῆς ἄρκτου. Γίνεται δὲ τὸ νόημα τὸ περὶ τοῦ ἀδελφοῦ θηριάλωτον, εἰ μετὰ μίσους νέμοι τὸ ἐν ἡμῖν, καὶ τὸ περὶ τῆς γυναικὸς, εἰ μετ' αἰσχρᾶς ἐπιθυμίας στρέφοιτο παρ' ἡμῖν, καὶ τὸ τοῦ ἀργυρίου, καὶ τοῦ χρυσίου, εἰ μετὰ πλεονεξίας αὐλίζοιτο. Καὶ τὰ νοήματα τῶν ἁγίων χαρισμάτων, εἰ μετὰ κενοδοξίας κατὰ διάνοιαν βόσκοιτο· καὶ ἐπὶ τῶν ἄλλων δὲ νοημάτων ὡσαύτως συμβήσεται, κλεπτομένων τοῖς πάθεσιν.  Εὐάγριος ὁ Ποντικός, Περὶ διαφόρων πονηρῶν λογισμῶν Source: Migne PG 79 1220

The thoughts of this world the Lord gave to man as sheep to a good shepherd, for it is written, 'He has placed the world in his heart;' 1 yoking to him indignation and desire for aid, so that with the first he may drive away the thoughts of the wolves, and with desire he may care for the sheep, even though he is often buffeted by rain and winds. God also gave him pasture so that he may shepherd the sheep, as well as a verdant place and refreshing water, 2 and a harp and a lyre, and a rod and a staff, so that from these sheep he is fed and clothed and supplied with food on the mountain. For it is written, 'Does anyone feed a flock and not drink its milk?' 3 It is therefore necessary for the one who has withdrawn that he be on his guard night and day over his flock so that thoughts are neither caught by wild beasts nor fall to thieves; and if such a thing happen, in the wooded valley he must immediately snatch them from the mouth of the lion or the bear. 4 So it is that the thought of a brother becomes of the beast if it pastures what is within us in hatred; as regards a woman, if we turn away from ourselves to shameful desire; and as regards gold and silver, if we take up our dwelling with avarice. And the thoughts of the holy gifts are likewise seized if we mentally graze on vainglory, and the same happens in the case of other thoughts if they are stolen away by the passions. Evagrius Ponticus, On Various Evil Thoughts 1 Eccl. 3.11 2 Ps 23. 2  3 1 Cor. 9.7  4 1 Kings 7.35