Hinduism has neither a common doctrine nor a single scripture as the source of its various teachings. It places more emphasis on orthopraxy than orthodoxy, encouraging relative freedom of thought within tightly defined codes of conduct and morality.

More than Western traditions, it has succeeded in synthesising religion with philosophy, and religious commitment with a reflective search for truth. It does not generally exhort its followers to declare allegiance to a particular faith, belief, or creed.

Many Hindus call their tradition santana-dharma, the eternal law that governs everyone irrespective of belief. These truths regarding the universal law were divinely revealed to ancient sages. For many aeons they were passed down orally and only later written down, apparently around the start of the Kali-yuga when people's memories began to deteriorate. Perhaps the most important sage was Vyasa (Badarayana), generally accredited with writing the Vedanta Sutras, Mahabharata and Bhagavad-gita.

As Hinduism developed, it did not reject its parent traditions, but modified and assimilated them into newer schools of thought. For example, the ancient Vedic notion of sacrifice, and the later philosophies of Sankhya and Yoga, have all been assimilated into the more recent school of Vedanta. Even the more sectarian sampradayas do not entirely reject other doctrines, but claim that they demonstrate a less complete understanding.

Despite a relatively inclusive approach, Hinduism has rejected those doctrines that do not accept its scriptural authority. Most notably these include Jainism, Buddhism, and the hedonistic philosophy of Charvaka. They are therefore called nastika, differentiating them from the accepted schools termed astika. There are six main astika systems, which are called darshanas (ways of seeing). The various groups and sub-groups within Hinduism usually subscribe to one or more of the six darshanas.

The Six Darshans

The six darshanas are grouped as three pairs of "sisters." Each pair consists of one darshan dealing with theory and the other explaining the corresponding practice and methodology. For example, Sankhya forms the doctrinal basis for the discipline of yoga. Each pair is further explored in this section.
Some groups consider these schools to be hierarchical, with Vedanta the culmination of Vedic philosophy. This is somewhat supported by the fact that Vedanta means "the end of the Vedas" or, less literally, "the ultimate conclusion of knowledge." Certainly, Vedanta today represents the more theologically developed strands of Hinduism, and forms the basis for many modern theistic traditions.

Darshan	Teacher	Teachings
Vaisheshika	Kanada	Physics,especially atomic theory
Nyaya	Gautama	Logic and epistemology
Sankhya	Kapila Muni	Physics and metaphysics
Yoga	Patanjali	Sadhana (spiritual practices)
Mimamsa	Jaimini	Hermeneutics and ritual
Vedanta	Vyasa	Metaphysics

Related Values and Issues

• Fact, opinion and belief
• Doctrine versus dogma
• Vedanta is closely aligned with its sister school, Mimamsa (meaning "enquiry").The two are often called Purva Mimamsa and Uttara Mimamsa, denoting the earlier and later schools of enquiry. The earlier Mimamsa deals with dharma and focuses on rituals, particularly for promotion to higher planets. Its main texts are from the Karma-kanda section of the Vedas.
  The later school, Vedanta, deals with Brahman and derives much from the Jnana-kanda section, especially the Upanishads and Vedanta Sutras (also known as the Brahma Sutras). Members of these two doctrines are traditionally at loggerheads, but they are essentially complementary. Much of modern Hinduism, though philosophically grounded in its Vedanta, borrows its ritualistic practice from Purva Mimamsa.
  There are ten principal schools of Vedanta. Of these, two are purely Advaita, one purely Dvaita and seven a synthesis of both. In Hinduism as represented in the UK, there are four important schools of Vedanta.
  

  The Four Main Schools of Vedanta Represented in the UK

  For any tradition to be accepted as a genuine Vedantic school, the founder must present commentaries on three scriptures – the Upanishads, the Vedanta Sutras, and the Bhagavad-gita, collectively called the "prasthana trayi."
  Below are the four main branches of Vedanta along with: (1) its founding theologian, (2) the sampradaya, (3) the main representative movement in the UK.
  

  School	Theologian	Sampradaya	UK Movement
  Advaita (monism)	Shankara	Smartas	Ramakrishna Mission
  Vishishtadvaita (qualified monism)	Ramanuja	Shri Vaishnavas	Swami Narayana Mission
  Suddhadvaita (purified monism)	Vallabha	Pushti Marg	Shree Vallabha Nidhi
  Achintya Bheda-abheda	Baladeva	Gaudiya Vaishnava	ISKCON (Hare Krishna Movement)

  Common Misunderstandings

  Vedanta (and all Hinduism) is entirely monistic, believing only in the all-pervading world-soul, Brahman, rather than a personal God

  This advaita philosophy is certainly popular, and offers a simple explanation of the many deities. Nonetheless, many theologians have considered God to be a person. He is not merely an anthropomorphic representation, nor are the various deities and murtis simply incarnations or representations of an impersonal Supreme.
  Thus Hinduism includes both monism and monotheism. It is misleading to call the Abrahamic religions,"the monotheistic traditions," implying that monotheism is absent from the Eastern traditions. Vedanta includes many monotheistic schools. They may accept the existence of many gods and goddesses, but strongly emphasise the pre-eminence of the Supreme Deity.Classifying the many groups within Hinduism is a challenge, and not so easy (as, perhaps, with other religions.) In so doing, we may inadvertently promote the idea that Hinduism is a single monolithic religion. It is, more accurately, a family of religions, with each family member autonomous but sharing distinctive family features.
  In discussing all religious groups, we may imply that they are static, homogeneous and well-defined "wholes." In actual fact, they are fluid and evolving traditions, internally diverse and contested, and hazy at the edges. In trying to discern specific strands within Hinduism, therefore, we are also in danger of over-generalising, promoting stereotypes and creating false boundaries. Nonetheless, it is useful – even necessary – to establish a somewhat tentative framework for categorising the numerous groups and sub-groups. Here we categorise them according to three criteria:
  

  1. focus of worship
  2. doctrine
  3. preferred process or practices

  Four main communities can be identified, each according to its respective focus of worship (these four communities are discussed in theVaishnavism, Shaivism, Shaktism, and Smarta pages). Each community, which we loosely term here a "denomination," favours its own specific deity or deities (below).
  

  The Four Main Denominations

  1. Vaishnavas worship Vishnu (usually as Krishna or Rama)
  2. Shaivas worship Shiva (often in the form of the linga)
  3. Shaktas worship Shakti, also known as Devi (especially Parvati, Durga, Kali)
  4. Smartas worship five deities i.e. Vishnu, Shiva, Devi, Ganesh, and Surya

  In the UK many individuals and temples will not specifically align themselves to one (or more) of these traditions. They worship deities from all these traditions. They often describe themselves as "Sanatanist" to reflect their more inclusive nature. Underpinning them, there is often a leaning towards the monistic Smarta conclusions of Shankara.
  Shaivism and Shaktism are often closely related, especially within tantric traditions, which explore the male-female symbolism of Shiva-Shakti.

  Six Doctrines and Four Paths

  
  Although Hinduism can be primarily classified into four main denominations according to their respective focuses of worship, there are two other criteria that help account for the tradition's diversity. They revolve around (1) the different doctrines, and (2) the various processes of realisation.
  

  Doctrines

  Advaita: Monists or Impersonalists

  who believe that,
  

  • God is ultimately impersonal.
  • the soul is entirely non-different from God (but has yet to realise/develop his Godhood).

  Dvaita: Dualists or Personalists

  who believe that,
  

  • God is ultimately personal,
  • the soul remains eternally distinct from God (though both are usually considered Brahman).

  There are six orthodox darshans (ways of seeing) to which the various groups and sub-groups subscribe. (They are outlined in detail in the Hindu Doctrine section). Of these, Vedanta is often considered the culmination and represents the theologically developed strands of contemporary Hinduism. Vedanta, however, has not entirely rejected the other five schools, but has tended to accommodate and assimilate them.
  Vedanta is often exclusively associated with the Advaita Vedanta of Shankara. However, there are two main approaches, as shown to the right. These two poles are combined in various ways to form ten main schools of Vedanta (see Vedanta and Mimamsa).
  For most purposes it is best to familiarise ourselves with the basic notions of these two schools, the impersonal and the personal. They can also be termed monism and monotheism, keeping in mind that the latter is almost always "inclusive monotheism" (see God: Two Main Understandings).
  

  Processes/Paths

  Within Hinduism there are diverse practices, but most fall within four main paths or margs. Since these are aimed at union (with God) they are also termed "yogas." They are:
  

  1. karma-yoga – the yoga path of action
  2. Jnana-yoga – the path of knowledge
  3. Raja (astanga) yoga – the path of meditation
  4. Bhakti-Yoga – the path of devotion

  Some authorities list only three paths by excluding Raja yoga, which is often closely associated with jnana-yoga, because of the common emphasis on renunciation (see also Four Main Paths).
  The four main denominations often favour one or more of these processes, and will also lean towards a particular doctrine (below).
  

  The Four Denominations and their Favoured Doctrine/Path

  • Vaishnavas are mostly personalists and favour the path of bhakti-yoga.
  • Shaivas are often impersonalists with tendencies towards jnana- and astanga yoga (closely linked to sankhya-yoga). There are, however, notable personalistic, bhakti strands, especially in South India (e.g. the Lingayats).
  • Shaktas tend to be impersonalists, and their worship often focusses on material benefit (karma-yoga). Their theology tends to be less developed and draws largely on Shaivism.
  • Smartas follow the impersonal (advaita) doctrine of Shankara and favour the path of jnana, featuring renunciation and philosophical inquiry.

  
  

  Source:-     http://hinduism.iskcon.com