Hindu philosophy refers to a group of darsanas (philosophies, world views, teachings) that emerged in ancient India. The mainstream Hindu philosophy includes six systems (saddarsana) Samkhya, Yoga, Nyaya, Vaisheshika, Mimamsa and Vedanta. These are also called the Astika (orthodox) philosophical traditions and are those that accept the Vedas as authoritative, important source of knowledge.[note 1][note 2] Ancient and medieval India was also the source of philosophies that share philosophical concepts but rejected the Vedas, and these have been called nastika (heterodox or non-orthodox) Indian philosophies. Nastika Indian philosophies include Buddhism, Jainism, Carvaka, Ajivika, and others.

Scholars have debated the relationship and differences within astika philosophies and with nastika philosophies, starting with the writings of Indologists and Orientalists of the 18th and 19th centuries, which were themselves derived from limited availability of Indian literature and medieval doxographies. The various sibling traditions included in Hindu philosophies are diverse, and they are united by shared history and concepts, same textual resources, similar ontological and soteriological focus, and cosmology. While Buddhism and Jainism are considered distinct philosophies and religions, some heterodox traditions such as Carvaka are often considered as distinct schools within Hindu philosophy.

1. how many parts in the main doctrine?
2. are the named?
3. what is one?
4. another?
5. the non mainstream philosophies are identified as?
6. what makes them different?
7. how many are named?
8. what is the first?
9. the second?
10. the third?
11. and the last one?
12. is something about kinfolk talked about?
13. what?
14. are they limited?
15. are they brought together?
16. by what?

Provide a numbered list of answers.
1. mainstream Hindu philosophy includes six systems
2. Yes
3. Samkhya
4. Nyaya
5. nastika
6. they reject the Vedas
7. Four
8. Buddhism
9. Jainism
10. Carvaka
11. Ajivika
12. Yes
13. sibling traditions
14. No
15. Yes
16. by shared history