Alongside Buddhism, people also practised Daoism. Many landscape paintings from the 10th century onwards show the influence of Daoist ideas about the yin yang balance believed to be at the heart of the nature of universe. Practising the Dao (the Way )was about understanding the natural order of the world while withdrawing from everyday politics, which many painters did. Daoist ideas of immortality can also be seen in works of the Han dynasty which portray immortals and strange creatures flying among heavenly clouds. The use of materials such as realgar and cinnabar or copies of them in works of art reflects the Daoist pre-occupation with finding elixirs of immortality. Paradoxically, taking some of these potentially poisonous substances led to the deaths of more than one Chinese emperor, including Qin Shihuangdi sculptures portraying Daoist figures such as the Eight Immortals or Star Gods became popular in the Ming and Qing dynasties.