Siddhas were mystics of ancient India. They believed that human race was created to excel in knowledge and help human societies form an advanced civilization on the Earth. They knew that they needed to live longer and even become immortals to achieve this goal.In Indian context Siddhas were considered as doctors but in Western context, such people were called Philosophers. Nevertheless, a deeper understanding of Siddhas' poetic scripts reveals their different faces such as scientific thinkers, social reformers, priest kings, pioneers of advanced cultures, etc. Siddhas speak about spirit, soul and body in their scripts. They also compare cosmos, nature and earth in their science.The unique attainment of Siddhas could be their mastery over physical and cosmic sciences. Siddhas believed that physical science is comparable with cosmic science. Thus, through their physical and cosmic observations, they succeeded in inventing ambrosia of Gods and many became Gods themselves.