Raghunatha Siromani (1477 – 1547) is a luminary in the field of Nyaya philosophy and was the head of the ancient Mithila University or Mithila Vidyapeeth. He was born in a poor family of at Nabadwip in Nadia district (West Bengal India) around 1477 CE. He lost his father when he was an infant. He was the grandson of Shuulapani, a noted writer on smriti from his mother's side. Tradition regards him as the student of Vasudeva Sarvabhauma, who is regarded as the first of what is called the “Nudden School.” At every stage of learning, Raghunatha proved himself to be an extraordinary student and very soon surpassed his teacher in many respects.
The method of study of Raghunatha Siromani was unique. After copying the text to be discussed, he used to find out the logical inconsistency of the text and present systematically his views on the subject covered by the text.
Raghunatha, although by conviction a Naiyayika, was extremely critical about certain Nyaya – Vaisheshika theories. For instance, he was critical of the concept of samanya lakshana, a method adopted in the Navya-Nyaya School for proving the vyapti (invariable unconditional concomitance), on which anumana (inference) is based.
Further, in his work Padartha Tattva Nirupana, he not only criticized some of the traditional Nyaya-Vaisesika categories but also added certain new categories such as shakti (power), samkhya (number) etc.
Among his works, Tattva Chintamani Didhiti, a critical commentary on Tattva Chintamani of Gangesha Upadhyaya, is extensively commented upon. His commentary on Book II often disagrees with Gangesha. In this work, he calls himself “Tarika Siromani” (the crest gem of logicians) and afterwards he was well known as Raghunatha Siromani. His other works include – Akhyatavada, Nan-vada, Padartha-tattva-nirupana, Atma-tattva-viveka-didhiti, Kiranavali-prakasha-didhiti, Khandana-khanda-khadya-didhiti and Nyaya-lilavati-prakasha-didhiti.
Raghunatha, though primarily a logician, wrote not only on logic but also showed a great interest in metaphysics, as seen from the titles of his works.