Saḍ-darśana-samuccaya (‘a collection of the six systems [of philosophy]’) As the various systems of Indian philosophy evolved and developed to voluminous proportions with intricate logic, there arose the need to produce brief compendiums containing the essence of all the systems, for the benefit of ordinary students of philosophy. Out of such compendiums, the earliest is the Sarvadarśanasamuccaya of Haribhadra (A.D. 750). This work is considered an important summary of the various systems. These six (ṣaṭ = six; darśana = philosophy) are: Bauddha, Naiyāyika, Sāṅkhya, Jaina, Vaiśeṣika and Jaiminiya. The work is in 87 kārikās or explana¬tory verses. Maṇibhadra and Guṇaratna (14th century A. D.) have written commen¬taries on it, the latter known as Tarka- rahasyadīpikā being more exhaustive. Another work of the same name by Rājaśekharasuri (13th century A. D.) has also been found. He has, in 180 ślokas (verses), dealt with the Jaina, Sāṇkhya, Jaimini, Yoga (= Saivism), Vaiśeṣika and Saṅgata (Bauddha) systems.