________________ PREFACE With this publication of the Nyayakandali (NK) and its three Commentaries along with the Padarihadharmasangraha, (PDS) the dream of late Dr. J. S. Jetly is materialized. It however, took twenty years for its fulfilment, as the outline of this project was prepared by him in 1970. He was kind enough to associate me with him in this project. After his untimely sad demise on 26th June 1972, it was only through his guiding spirit and constant encouragement from the Director of the Oriental Institute, Baroda, that I could reach the completion of this monumental work. Dr. Jetly was a devout scholar of the Nyaya-Valsesika philosophy. His main concern was to find out and edit the unpublished texts of this system, that are preserved in the form of manuscripts at different places. His thirst for research was almost nostalgic. He had personally visited nearly all the impor. tant Bhandarus of India in search of some valuable manuscripts. He spent a few months in 1950-51 at Jaisalmer to rearrange the mss. of its reputed Bhandara. In course of his exploration of the precious treasure of Mss., in this Bhandara, he came across a Ms. of the Kiranavali (a commentary on the PDS) of Udayanacarya. To his pleasant surprise, Dr. Jetly found out that, the Ms. contained some more portion than the printed texts of the Kiranavali, available at that time. The Ms. was complete upto the end of the Guna prakarana, while all the printed texts ended with the topic Buddhi of the Guna Prakarana. Dr. Jetly edited the Kiranavali in the fresh light of this Ms., and it was published in GOS. [ No. 154] by the Oriental Institute, Baroda in 1971. The Kiranavali of Udayana is one of the four well-known commentaries on the PDS. It is therefore, a matter of great pleasure that now one more commentary on the PDS, i.e. the Nyayakandali edited by Dr. Jetly, is published in GOS, by the Oriental Institute, Baroda. Thus the publishing of this volume, it seems, has taken the form of the most befitting tribute to the scholarship of the late Dr. Jetly. In the Introduction to his edition of the Kiranavali, Dr. Jetly has remarked ** The study of the Vaisesika system was made popular with the help of Prasastapada. Though it is the digest of VS., for the study of the system, it proved to be the worst enemy of the Sutra-text." (P. XI). The four commentaries, therefore are very useful to present a comprehensive picture of the Vaisesikasutras. The Nyayakandali of Sridhara has played a specific role in preserving the classical edifice of the Nyaya-Vaisesika philosophy, against the vehement criticism of opponents like the Mimamsakas and the Bauddhas. It is natural, therefore,