Hindu philosophy also includes several sub-schools of theistic philosophies that integrate ideas from two or more of the six orthodox philosophies, such as the realism of the <answer>Nyāya</answer>, the naturalism of the Vaiśeṣika, the dualism of the Sāṅkhya, the monism and knowledge of Self as essential to liberation of Advaita, the self-discipline of yoga and the asceticism and elements of theistic ideas. Examples of such schools include Pāśupata Śaiva, Śaiva siddhānta, Pratyabhijña, Raseśvara and Vaiṣṇava. Some sub-schools share Tantric ideas with those found in some Buddhist traditions. The ideas of these sub-schools are found in the Puranas and Āgamas.
Which orthodox Hindu philosophy concerns realism?
Nyāya