According to Vasubandhu’s presentation of Vaibhashika, ignorance is a disturbing mental factor that stupefies the mind. Because it opposes and prevents straightforward cognition of the sixteen aspects of the four noble truths, it is an anti-knowing mental factor. By its own power, it does not take its object in a reversed manner. Although it accompanies the mental factor of disturbed discriminating, it is a distinct mental factor from it.