The basic principle of Hinduism is the belief in one supreme being who is without forms or attributes, worshipped in any one of several of His forms of manifestations. They believe that God accepts every one's prayer to every form they worship. They believe in nonviolence or Ahimsa, in vegetarian food habits, and in compassion to all lives. They believe in Divine duty or Dharma and activity without attachment or Karma yoga and the need for a devotion and surrender to God or Bhakthi. They believe in the indestructibility of the soul, cycle of rebirth and the ultimate liberation of the Soul or Moksha. The basic philosophies are given in the various Upanishad portions of the Vedas. Ancient Sages wrote the six Dharsanas as explanatory texts for these Upanishads. Vaiseshika, Sankhya and Vedantha Dharsanas deal with theoretical aspect of the religious faith, prayers and the philosophy. Nyaya, Yoga and Poorva Mimamsa systems explain the practice of the faith with analysis, logic and pure rituals. They did not stress the importance of a concept of prayers to God.

Nyaya system by Rishi Gauthama is the science of debate, logic and discussion with reasoning and arguing. Vaiseshika by Rishi Kanada arranges its inquiries into categories such as substance, quality, action, property and nonexistence. They were the analytical Systems. Sankhya by Rishi Kapila is called a synthetical system starting from a primordial principle called prakrithi which evolves and brings forth everything, when it comes in contact with Purusha. The Yoga system by Sage Pathanjali is a supplement to Sankhya, laying emphasis on the practical side of self discipline and concentration. Poorva Mimamsa of Sage Jaimini lays stress on the Vedic rituals and sacrifices as the ultimate for the liberation and eternal happiness. They did not deny a God but just ignored His existence. Other Mimamsakas modified Sri Jaimini's theory later to introduce the concept of God in rituals. Utthira Mimamsa or Vedantha of Sage Vyasa or Krishna Dvaipanya explained the Hindu Philosophy.

Sri Vyasa Maharishi founded the System of Vedantha which is the most popular Vedic Philosophy. He also wrote the Dharma Sasthras based on the Vedantha. They are followed by most Hindus as their Philosophy, though many rituals and principles of other systems are also used. According to Vedantha, Brahmam develops Itself into the universe for Its own sporting or lila without undergoing any change and without ceasing to be Itself. It is the material and instrumental cause of the universe. The reality appears to our limited intelligence as the finite universe of time and space due to the mysterious power of Maya of God. It is due to avidya or ignorance, a natural disability of our soul that prevent it from comprehending God as He really is. When the natural limitations of avidya are removed through real knowledge, the individual is no longer there as a separate entity but becomes one with Paramatma.

Many Acharyas wrote detailed explanatory texts on these to establish the philosophy and practice of the faith. Sri Sankara wrote the Advaitha theory. In this, the Brahmam is absolute and formless. He appears as the Saguna Brahmam in various forms for the pious worship of devotees. The Supreme Brahmam and all His creations are one and the same. They look different due to the veil of Maya and due to our ignorance or avidhya. Sri Ramanuja wrote the Visishta-adhvaitha. In this, Brahmam is Narayana, a personal God with attributes. It is not homogenous, has elements of plurality and manifests in a diversified world. Sri Madhva's Dhvaitha is strictly dualistic. The individual souls do not attain equality with God. Here God is separate from His creations, who are real and dependent on God. We also have other systems that are slightly different including the Saiva Siddhantha of Sage Meykandar in Tamil Nadu and Sakthi Yoga Philosophy which follow Saivism and Sakthism.