 The Yoga school shares much with the Sāṃkhya regarding the nature of the true self and the individual person, differing in its emphasis on the yogic practices (psychophysical techniques centering on meditation) as the means of discovering the true nature of the real self. The Sāṃkhya and Yoga philosophers disagree with the Advaitic thesis that individual persons (jīvas) are only delusions, but agree that the true self, the essence of the person is the soul or consciousness untainted by matter. There is no value to development of persons as such, according to these spiritual philosophies, the only activity worthy of pursuit is the search for the true self.