In particular, when reason denies intuitive knowledge and ‘‘blinds the eye of the heart’’, it becomes the target of strong criticism from Sufism. This stands in stark contrast to the Aristotelian and contemporary western emphasis on logical reasoning as the highest human faculty, which should rule the whole personality. On this basis, happiness cannot be achieved by reason and intellect, rather happiness is pursued via intuition and mystical experience.[6] Another important concept in Sufism is the ego (the self or the nafs).