The concept of yantra in the Samarāṅgaṇa-Sūtradhāra of Bhoja
Natural philosophy and occult art are the two basic factors in the concept of yantra formulated by Bhoja in hid Samarāṅgaṇa Sūtradhāra. The former is represented in the idea of five elements as the constituent elements of yantras. The latter is revealed in the treatment of the entire theory of bīja in the formation of yantras in the way resembling the alchemical notion of bīja for bringing out different alchemical preparations.
This philosophy of bīja (constituent elements) in the concept of yantra is the subject of discussion of the present paper.
Indian Journal of History of Science, Vol. 19, no. 2 (1984), 118–124.