Vedas (The most sacred scriptures of Hinduism are the Vedas ("Books of Knowledge")

What are the Vedas?

The most sacred scriptures of Hinduism are the Vedas ("Books of Knowledge"), a collection of texts written in Sanskrit from about 1200 BCE to 100 CE. As sruti, the Vedas are regarded as the absolute authority for religious knowledge and a test of Hindu orthodoxy (both Jains and Buddhists reject the Vedas). "For Hindus, the Veda is a symbol of unchallenged authority and tradition." {1}
Selections from the Vedas are still memorized and recited for religious merit today. Yet much of the religion presented in the Vedas is unknown today and plays little to no role in modern Hinduism.
As historical and religious literature often is, the text is written from the perspective of the most powerful groups, priests and warrior-kings. Scholars say it is therefore unlikely that it represents the totality of religious belief and practice in India in the first millennium BCE. This perspective is especially evident in the earlier parts of the Vedas, in which the primary concerns are war, rain, and dealing with the "slaves," or native inhabitants of India.
Initially, the Vedas consisted of four collections of mantras (Samhitas), each associated with a particular priest or aspect of ritual: Rig Veda (Wisdom of the Verses); Sama Veda (Wisdom of the Chants); Yajur Veda (Wisdom of the Sacrificial Formulas); and Atharva Veda (Wisdom of the Atharvan Priests).
Over the centuries, three kinds of additional literature were attached to each of the Samhitas: Brahmanas (discussions of the ritual); Aranyakas ("books studied in the forest"); and Upanishads (philosophical writings).
In these later texts, especially the Upanishads, the polytheism of the earlier Vedas has evolved into a pantheism focused on Brahman, the supreme reality of the universe. This concept remains a key feature of Hindu philosophy today.

Samhitas

As noted above, the Samhitas ("Collections") are the oldest components of the Vedas, and consist largely of hymns and mantras. There are four Samhitas (also called Vedas): Rig Veda, Sama Veda, Yajur Veda, and Atharva Veda.

The Rig Veda

Composed as early as 1500 BC, the Rig Veda or Rg Veda ("Wisdom of the Verses") is the oldest of the four Vedic collections and one of the oldest surviving sacred texts in the world. The Rig Veda consists of 10,552 verses (collected into 10 books) of hymns and mantras used by the hotri priests.
The hymns of the Rig Veda focus on pleasing the principal gods Indra (war, wind and rain), Agni (the sacrificial fire), Surga (the sun) and Varuna (the cosmic order) through ritual sacrifices. Along with governing important matters of life such as rain, wind, fire and war, the Vedic gods also forgive wrongdoing (5.85.7) and mete out justice in the afterlife (1.97.1).
Deceased ancestors are able to influence the living (10.15.6), so they are also appeased with rituals (10.15.1-11). The afterlife of the Rig Veda is eternal conscious survival in the abode of Yama, the god of the dead (9.113.7-11). It is the gods, not karma, that are responsible for assuring justice in this life and the next (7.104).

Yajur Veda and Sama Veda

Both the Yajur Veda ("Wisdom of the Sacrifical Formulas") and the Sama Veda ("Wisdom of the Chants") are liturgical works consisting primarily of selections from the Rig Veda. The Yajur Veda was used by udgatri priests and contains brief prose to accompany ritual acts, many of which are addressed to the ritual instruments and offerings. The Sama Veda was chanted in fixed melodies by the adhvaryu priests. Each contain about 2,000 verses.

Atharva Veda

The Atharva Veda ("Wisdom of the Atharvan Priests) was added significantly later than the first three Samhitas, perhaps as late as 500 BC. It consists of 20 books of hymns and prose, many of which reflect the religious concerns of everyday life. This sets the Arharva Veda apart from the other Vedas, which focus on adoring the gods and performing the liturgy of sacrifice, and makes it an important source of information on the practical religion and magic of the time.
Books 1 through 8 of the Atharva Veda contain magical prayers for long life, prosperity, curses, kingship, love, and a variety of other specific purposes. Books 8 through 12 include cosmological hymns, marking a transition to the loftier philosophy of the Upanishads. The remainder of the books consist of magical and ritual formulas, including marriage and funeral practices.

Brahmanas

The mythology and significance behind the Vedic rituals of the Samhitas are explained in the Brahmanas. Although they include some detail as to the performance of rituals themselves, the Brahmanas are primarily concerned with the meaning of rituals. A worldview is presented in which sacrifice is central to human life, religious goals, and even the continuation of the cosmos.
Included in the Brahmanas are extensive rituals for royal consecration (rajasuya), which endow a king with great power and raise him to the status of a god (at least during the ceremony). Part of the ritual is the elaborate horse sacrifice (asvamedya), in which a single horse is set free, followed and protected by royal forces for a year, then ritually sacrificed at the royal capital.

Aranyakas ("Forest Books")

The Aranyakas contain similar material as the Brahmanas and discuss rites deemed not suitable for the village (thus the name "forest"). They also prominently feature the word brahmana, here meaning the creative power behind of the rituals, and by extension, the cosmic order.

Upanishads ("Sittings Near a Teacher")

The word "Upanishad" means "to sit down near," bringing to mind pupils gathering around their teacher for philosophical instruction. The Upanishads are philosophical works that introduce the now-central ideas of self-realization, yoga, meditation, karma and reincarnation.
The theme of the Upanishads is the escape from rebirth through knowledge of the underlying reality of the universe. The Encyclopaedia Britannica explains how this change in perspective came about:
Throughout the later Vedic period, the idea that the world of heaven was not the end-and that even in heaven death was inevitable-had been growing. For Vedic thinkers, the fear of the impermanence of religious merit and its loss in the hereafter, as well as the fear-provoking anticipation of the transience of any form of existence after death, culminating in the much-feared repeated death (punarmrtyu), assumed the character of an obsession. The older Upanishads are affixed to a particular Veda, but more recent ones are not. The most important Upanishads are generally considered to be the Brhadaranyaka ("Great Forest Text") and the Chandogya (pertaining to the Chandoga priests). Both record the traditions of sages (rishis) of the period, most notably Yajñavalkya, who was a pioneer of new religious ideas. Also significant are:
- Mandukya Upanishad
- Kena/Talavakara Upanishad
- Katha Upanishad
- Mundaka Upanishad
- Aitareya Upanishad
- Taittiriya Upanishad
- Prashna Upanishad
- Isha Upanishad
- Shvetashvatara Upanishad