The Upanishads are a collection of ancient Indian texts that explore the nature of reality and the relationship between the individual and the universe. They teach that the ultimate reality is Brahman, a single, unified consciousness that pervades all things.

The Atman is the individual soul, the essential self that is present in all living beings. It is often contrasted with the Brahman, the universal soul, which is the ultimate reality.

The Upanishads teach that the Atman and the Brahman are ultimately identical. This means that the individual soul is a part of the universal soul, and that all things are connected in a single, unified consciousness.

The Upanishads teach that the goal of human life is to gain knowledge of the self and the universe. This knowledge leads to liberation from the cycle of reincarnation and union with the Brahman.

The doctrine of karma is the belief that good deeds lead to good results and bad deeds lead to bad results. This doctrine is based on the idea that the soul transmigrates from one body to another after death, and that the experiences of the soul in each life are determined by the actions of the soul in previous lives.

The doctrine of reincarnation is the belief that the soul transmigrates from one body to another after death. This doctrine is based on the idea that the soul is immortal, and that it continues to exist after the death of the body.

The doctrine of moksha is the belief that the soul can achieve liberation from the cycle of reincarnation. This liberation is achieved through the realization of the identity of the Atman and the Brahman.

The Atman is the universal soul, not the individual soul. The individual soul is called the jiva.

The performance of rituals is not a way to achieve moksha. Moksha is achieved through knowledge of the self, devotion to God, or selfless action.

People's social status is not determined by their karma. Karma is a personal matter, and it does not affect a person's social status.

The Bhagavad Gita is not a major Upanishad. It is a part of the Mahabharata, an epic poem.

Nyaya is a school of Indian philosophy that focuses on logic and epistemology. It does not discuss the concept of Atman.

Nagarjuna is a major figure in the history of Buddhist philosophy, not Indian philosophy. He did not discuss the concept of Atman.

Nyaya Sutra is a major text in Indian philosophy that discusses logic and epistemology. It does not discuss the concept of Atman.

Samsara is a major concept in Buddhist philosophy, not Indian philosophy. It refers to the cycle of birth, death, and rebirth.