Buddhist philosophy emerged from the main Indian views which are given here.
What is Philosophy?
Philosophy is an activity of the intellect where, using argument and clarification, we strive to reach conclusions about the nature of existence. It employs discussion and debate to build on past argument. It comprises a number of topics such as ethics, aesthetics and logic, but it is metaphysics -- what the ultimate nature of the whole of Reality is and how it functions -- that is our concern here, for it includes the important sub-topic concerning existence/being, known as ontology.
Writings on Buddhist philosophy are generally found under the heading of abhidharma, [further, or commentaries on, the Buddha's doctrine.] This is like any other kind of philosophy in that it strives to clarify the essential nature of being and of being-events or phenomena, but within the context of the Doctrine. Since it is the heroic figure of the Buddha, The Awakened One, that is our inspiration Buddhism especially asks, "What is the ultimate or enlightened nature of the exist-er?"
The distinctive Buddhist view, as compared to other kinds of Indian philosophy, is called The Middle Way or in Sanskrit, Madhyamika. How that Way actually functions is at the very root of the various distinctive schools, "Chariots," lineages and so on. Let us first see the context out of which this approach emerged.
Orthodox Indian Views
Put very simply, the most commonly held view in Indian philosophy holds that there is an ultimate Self, God or Cosmic Essence that we should seek to know, to marry with, or become absorbed into. This is the Dvaita or Dualist view. The particular nature and form (or lack of one) that the Highest Being embodies can serve as an identifier of the religious sect to which a person belongs. Many Hindu schools hold that the Highest Self also resides in individuals. Some teach that the ultimate goal is extinction of the individual Self. Many sects teach that the ultimate duty of human beings is to worship this Self.
Advaita or the non-dual view is a contrasting belief that holds that the person and the deity are one and the same in substance and nature.
Hindu philosophy comprises the traditional Six Views [Skt. darshanas]:
Nyaya (method using logic and syllogism) is attributed to the philosopher / sage called Akashapada Gautama. It regards perception including meditation as a reliable means of cognition to disclose things as they really are. However, any conclusion must follow through the application of logic.
Vaisheshika [pron. vyshka] was established by Kanada. It is an analytical system that considers each phenomenon -- existing appearance, person, event or being -- to possess a characteristic of reality called 'uniqueness' (vish'sha) or 'value.' Its name is similar to a word used for merchant whose role is to note characteristics.
Samkhya, attributed to the legendary sage called Kapila, is what is generally thought of when we hear the term, 'Indian philosophy'. It holds that reality is composed of 2 inter-actors: Prakriti (matter) and Purusha (mind). Prakrit consists of Akasha or primal matter, and Prana, primal energy. Each has 3 qualities or gunas [ropes, fetters]: tamas [dark /inert], rajas [fiery /active], sattvas [light/pure]. It is non-theist.
Yogacara [Unifying Practice] is the system of self-realization by means of the examination of the nature of the self. It derives from meditations originally (ie., in orthodox Indian religion) directed towards a union of individual consciousness with the Divine.
Mimamsa - 'inquiry' is also a methodology. It was founded by the Rishi Jaimini. Karma-mimamsa refers to the Indian doctrine that an individual ought to aspire to live according to the role they have been assigned by birth, therefore there is an emphasis on astrology.
Vedanta searches for transcendental knowledge stored in the Upanishads that are Indian teachings usually dated to around the time of Buddha Shakyamuni. That is, between the 8th and 4th centuries BCE. This school is said to be founded by the sage, Badarayana. It is considered as derived from, and complementary to, the ancient hymns or psalms called the Vedas. Its impact on the West in the early 20th century is usually credited with having initiated the interest in Indian religion, mythology and philosophy which then led to the watered-down and somewhat confused contemporary revival known as the New Age movement.
An important concept related to the Hindu views is that of maya or illusion. Our experience of the interplay of mind and substance as real, and hence important, is variously ascribed to the intentions of a playful goddess, to the actions of a malicious deity or to our own ignorance. Though most of us are inclined to be taken in, the ultimate objective is to attain the wisdom that brings with it Truth, Consciousness and Bliss (Skt.: sat, chit, ananda.)
Or else, to achieve moksha -- liberation or release from the round of rebirth that is partly a consequence of our ignorance.
Jain philosophy, the view of the Tirthankas (Skt: crossing-makers) is not covered here, though the Buddha's teachings contain references to it. During the Buddha's lifetime, many of the important towns that he visited were dominated by visitors to the great monuments of Jain 'heroes' or saints. Ahimsa, the doctrine of non-violence is most important; it protects life in all its forms.
It is an atheistic religion that promotes perfectibility in an ascetic sense. The Bogomils, Cathars and other gnostic groups of Europe bear this influence.
The Buddhist View
According to Buddhism, there is not a Something-to-Attain, but also there is not Nothing-at-all. However, there are divergent views concerning whether what we perceive to be real is only a product of our minds, or whether this awareness is somehow more than just that.
The Gelugpas (Kadampa) of whom the Dalai Lama is the most prominent, hold the view called in Tibetan, Rangtong -- Empty of Self. Because he and other proponents such as Robert Thurman are the most widely read in the West, it may be assumed incorrectly by students of Dharma that that is the only version of the Buddhist philosophical view.
The other widespread interpretation is called Shentong -- Empty of Other, and it is widely held among Kagyupas and some others.