Surah 7. Al-A'raf, Ayah 173

The latent faculties in man are enough to teach him the distinction between good and evil, to warn him of the dangers that beset his life. But to awaken and stimulate them, a personal appeal is made to each individual through the "still small voice" within him. This in its uncorrupted state acknowledges the truth and, as it were, swears its Covenant with Allah. There is, therefore, no excuse for any individual to say, either (1) that he was unmindful, or (2) that he should not be punished for the sins of his fathers, because his punishment (if any) comes from his personal responsibility and is for his own rejection of faith and the higher spiritual influences.