Information about the author of the book "History of the Mediaeval School of Indian Logic", available below, is provided here. This may help readers to better evaluate the contents of the book.

"Satish Chandra Vidyabhusan (30 July 1870 - 25 April 1920) was a Bengali scholar of Sanskrit and Pali Language and principal of Sanskrit College.

Vidyabhushan was known for his distinguished knowledge in Indian logic and Tibetan Buddhist Text. He, along with Sarat Chandra Das, prepared Tibetan-English dictionary. Vidyabhusan went to Sri Lanka in 1910 for study and on his return he was appointed the Principal of Sanskrit College, Kolkata. He became the Assistant editor of the Buddhist Text Society. He edited magazine of Bangiya Sahitya Parisad for 22 years. Vidyabhushan was a linguist having knowledge in Buddhist literature, Chinese, Japanese, German and French language. Vidyabhushan number of books on Buddhist Tibetan culture, logic, Sanskrit and Systems of Indian Philosophy. In 1906 he received the title of Mahamahopadhyaya. and got Ph. D in 1908."

         (from Wikipedia)

     History of the Mediaeval School of Indian Logic