Although Hinduism is referred to as a religion, it is often difficult to figure out just what is or is not Hindu. There is no gate-keeping institution that determines what is or is not a form of Hinduism. The religious perspectives of the Buddha, for example, seem clearly to stem from the Indian religious tradition, but are thought to be a distinct religion. Yet Hinduism seems not to define itself doctrinally. Hinduism seem to be defined as the religion that emerges from the subcontinent of India, and is formed around the Indian social system. (Buddhism’s deviation seems not to have been doctrinal, but rather has to do with the Buddhist rejection of the caste system).
However, there seems to be a certain flavor of character to Hindu religion, having to do with the doctrine of reincarnation. Old joke:
Christian: I’ve been born again.
Hindu: That’s nothing. I’ve been born again, and again, and again, and again, and again!
Exactly why Hinduism acquired the characteristics that it did is mysterious to me. What we know is that there was an indigenous culture in the Indus river valley, and that the Aryans invaded and became dominant. The features of the religion of the Vedas seem to be an unremarkable form of polytheistic religion, not much different from the Greek mythology. Vedic ritual included:
1) Sacrifices to nature gods
2) A hereditary priesthood
3) Outdoor fire altars
4) Memorized Vedic chants
5) Offering of food, drink, and animals to the gods
Yet, there seems to be a strand of critical reflection on this religious heritage even in the original religious writings of the Hindus, the Vedas. Rather than a confident statement about how the world was created, such as the biblical “In the beginning God created the heavens and the earth”, we instead get a passage about how the universe was formed from the God Purusha. But it is then stated that no one knows how this happed except Purusha, or perhaps, he doesn’t know either!”
The Axis was around 500 B. C. E. This was the time of the Buddha, Confucius, the Hebrew prophets, and the earliest Greek philosophers. In any event, a polytheistic world-view was beginning to be questioned. There were questions about the value of the Vedic sacrifices, and even the belief in many gods. Instead they sought a single divine reality that might be the source of everything. They spent a lot of time alone in the forest contemplating.
Also, these Hindus develops methods of altering consciousness (sitting for long periods of meditation, breathing deeply, fasting, avoiding sexual activity, practicing long periods of silence, going without sleep, using psychedelic plants, and living in dark caves).
The Upanishads were written at this time. The word means “sittings near a teacher” and were filled with teacher-student dialogues.