Innate Knowledge of Good and Evil

وَنَفْسٍ وَمَا سَوَّاهَا فَأَلْهَمَهَا فُجُورَهَا وَتَقْوَاهَا قَدْ أَفْلَحَ مَنْ زَكَّاهَا وَقَدْ خَابَ مَنْ دَسَّاهَا (91: 7-10)

And the soul bears witness and the perfection given to it, then [God] inspired it with its evil and its good that he succeeded who purified it and he failed who contaminated it. (91:7-10)

بَلْ الْإِنسَانُ عَلَى نَفْسِهِ بَصِيرَةٌ وَلَوْ أَلْقَى مَعَاذِيرَهُ (75: 14-15)

In fact, man himself is a witness upon his own self however much he may put forth [lame] excuses. (75:14-15)