Drona is regarded as the first test tube baby (theoretical). Drona's demand of guru dakshina from Ekalavya, in the form of his right thumb, is also scrutinized. In some folklore, Saraswati cursed Dronacharya with an unarmed and humiliating death for Drona's actions. Saraswati said that knowledge belonged to all, and that it was an acharya's duty to spread that knowledge everywhere. Despite whatever reasons he gave, Drona cheated Ekalavya and Karna to achieve something for himself-to protect his promise to Arjuna that he would make Arjuna the world's greatest archer, as well as his oath to Hastinapur.