Good and evil thoughts are in the minds of all creatures. Withdrawing the mind from cvil thoughts, it should always be bent towards good thoughts.
मानसं सर्वभूतेषु वर्तते वै शुभाशुभम्। अशुभेभ्य: सदाऽऽक्षिप्य शुभेष्वेवावतारयेत्॥