Hinduism is probably the world's oldest organized religion that has stood the test of time. The western concepts of a holy law book containing all the rules of the religion is not applicable to Hinduism. Instead, Hinduism is a religion based on allegorical connotations and its teachings are spread over numerous religious texts. Due to the sheer number of religious teachings and the number of years that have passed since the religion first came to existence, all aspects of the religion are based on relativity. There is no place for absolutism and every object in the Hindu universe is quantifiable and relative. In fact, the word Hindu itself is relative and was given to the people living in the east of the river Sindh by the Arabs. Thus, Hinduism did not arise from a Prophet or any singular law giver. Even the Supreme Court of India considers Hinduism to be a way of life and not a religion. It is the relativity of this scale that defines the relationship of the individual (atman) with that of the divine (Brahman).
The connection between the Atman and the Brahman.
According to the religious texts of Hinduism, time is neither constant nor linear but a circular repetitive phenomenon and is above everybody. All beings go through cycles of birth, death and rebirth. From the tiny fly with a lifespan of a few days to the mighty lord Brahma, all go through these cycles.
Atman in Hinduism means the soul of an individual. The Brahman on the other hand is the ultimate reality. While both are technically metaphysical concepts, the atman is considered to be a miniaturized version of the Brahman. A common analogy used to depict this relation is that of a drop of water in the ocean. The drop of water is the atman and the ocean is the Brahman. This also signifies the insignificance of the atman in relation to the Brahman. However, just as a drop of water falling in the ocean sends ripples that alter the entire surface of the ocean, the acts of the atman to have a profound bearing on the Brahman. This relation between the microcosmic atman with the macrocosmic Brahman points towards the simultaneous insignificance and the profound significance of the two entities. This connotes a dualistic as well as a non dualistic proposition that is central to the Hindu teachings.
Vedanta schools of thought
Vedanta literally means the end of the vedas and contains the culmination of the teachings of the Upaniṣads and their general context. The Vedanta does not imply a singular doctrine of a law book but encompasses the entire spectrum of the relationships between the atman and the brahman of the monistic and dualistic schools of thought. The unifying string of the Upaniṣads, the Brahma Sutras and the Bhagavad Gita is called the Prasthantrayi and is connoted in the Vedanta.
Vedanta deals with the relationship between the brahman and the atman and the divergence of thought with respect to this relationship is the basis of difference between the vedantic schools of thought.
Advaita Vedanta
It is a school of thought, first propounded by Adi Shankracharya, that believes in the non dualistic relationship between the atman and the brahman. It says that the Brahman is the Supreme entity that is the epitome of existence. Each particle of the Brahman which is called as atman by other schools is also the Brahman according to Advaita Vedanta. The goal is to self realize the true potential of the atman and transcend into the realm of the Brahman. The brahman cannot be taught or learned but only be realized. This realization can be achieved but the expulsion of all avidya (falsehoods) from the atman. Thus, there is no distinction between the atman and the brahman except that of a lack of knowledge. Once the realization has been made, the atman and the brahman are one. The central tenet of Advaita Vedanta is ekam sat (one truth). The brahman is is Advaita Vedanta is nirguna i.e.it has no attributes that are associated with distinctions. The distinctions are falsehoods in the quest for achieving self realization.
Vishistadvaita
First elucidated by Shri Ramanujacharya, it is also known as qualified monism that proposes the non dualistic nature of the relationship between the atman and the brahman. A distinctive feature of the Vishishtadvaita in comparison to that of the Advaita Vedanta is the belief in a sagun brahman that is a God with attributes. The crux of this philosophy is the argument that accepts the relationship between the surroundings (prakriti) with the atman that lead to a sagun brahman. It also never denies the acceptance of a nirguna brahman but only adds that the Brahman can also be sagun making both arguments metaphysically true. The path to achieving oneness with the brahman is propounded as bhakti (complete devotion) to the God.
Shuddhadvaita
First propounded by Shri Vallabhacharya, this school of thought proposes pure non dualism. It adds to the Advaita Vedanta the theory that the prakriti is not a separate metaphysical entity but an extension of the all encompassing Brahman. Thus it states that all components of this universe are a manifestation of the Brahman. It also rejects asceticism in favor of bhakti which it considers to be the purest path to salvation by knowledge (jnana). The goal of bhakti in shuddhadvaita is the renunciation of falsehoods and disbeliefs in the quest of complete devotion to Krishna who is the epitome of Brahman.
Dvaita Vedanta
Given by Shri Madhvacharya, the proponents of Dvaita Vedanta hold beliefs that are similar to the beliefs of the other major religions of the world. They believe that the Brahman is the Supreme entity and the atman is the smallest unit of the Brahman and is completely dependent on it for its existence. The distinction it holds against Vishishtadvaita is the acceptance of a qualitative and well as a quantitative pluralism of souls while Vishishtadvaita only accepts quantitative dualism of souls and rejects qualitative pluralism.
Dvaitadvaita Vedanta
Given by Shri Nimbarkacharya, this school of thought incorporates the philosophy of Bhedabheda (difference and non difference) into the teachings of the Advaita. It proposes the existence of three distinct entities namely, the eternal God (Brahman), the souls (chit) and the material world devoid of soul(achit). These three entities are related by cosmic order as the Brahman overseeing the enjoyment of the achit by the chit in consonance with the cosmic rules (Rta). It states that only by relentless devotion and subjugation to the one true knowledge can one achieve oneness with the Brahman.
Achintya Bhedabheda
It was first given by Shri Chaitanya Mahaprabhu who stated that Krishna is the cosmic truth and manifests as Bhagwan for how followers of bhakti and as Brahman for the followers of Jnana. The concept of Krishna is that of Bhedabheda as in Krishna is a part of everything that exists (Abheda) and yet he is distinct (Bheda) due to the inconceivability of his divine existence.
Relative Importance of the Individual Being in the Larger Scheme of Things
Due to the non definitive nature of the Hindu religion, there exist a large body of texts both supporting and opposing the role and significance of the individual in the larger scheme of things. However, according to the nastika tradition, the absence of proof of God is seen as the display of the individual's significance. This gains traction when read against the argument that explains the existence of the atman as a both the fundamental constituent as well as the miniaturised replica of the Brahman. According to both these arguments, the role of the individual is definitely not insignificant and has a bearing on the universe.
If we were to accept a man as an example of the individual, evidences of his modification of his surrounding (prakriti) for his enjoyment (bhogya) pop out. If however we take man as the atman of the dualistic school of thought, he emerges as someone yearning to achieve oneness with the Supreme being which can be allegorically taken as happiness. This quest for oneness with the Brahman can also be scrutinized under the lens of the hierarchical nature of a family. The man is conceived as a being without attributes (nirguna) and later gains attributes due to the effects of his surroundings (chit and achita). This ascribing of attributes to the man forces him down a path of existence as an insignificant cog in the grand machination that is the universe. This drives him away from oneness with the Brahman and makes him strive for oneness with the Brahman to achieve collinearity and restore order in his Universe but not the entire universe. On his death, the man again loses all his attributes has gains oneness with the Brahman. This cycle of transformation from nirguna to saguna and back to nirguna is a callback to the cyclical nature of existence of the universe.
If the man were to want to achieve oneness with the Brahman in his lifetime, he must do one of two things depending on the vedantic schools of thought. He may strive for ultimate knowledge (Jnana) or ultimate devotion to the Lord (bhakti). This presents the argument that the atman is in control of his choices and cannot be considered to be insignificant in the grand scheme of things.
The man's significance can also be ascertained from the train philosophies of dharma (right philosophy) and karma (right action). Had the man or rather the individual been relegated to insignificance, there would not have been the path to significance through dharma and karma. The equal emphasis on dharma as well as karma imply that the path to oneness is not achievable through only the right conduct but also requires the right thought. Oneness with the Brahman cannot be achieved only by mechanical following of noble tasks but requires one to cleanse his soul of all ignoble thoughts. The essence of dharma and karma are adequately enumerated in the Upaniṣads. Going by allegory, even the literal translation of the word Upaniṣads means something that is learnt by sitting close to the teacher. This relationship between the student and the teacher during the transfer of the the knowledge of the Sruthis,can also be used to explain the significance of the microcosmic student in relation to the macrocosmic teacher (Acharya). Had there been no students, there would have been no teachers and all learned men would have lived their lives as sadhus (ascetics) instead of as the Acharya. During the transfer of the Sruthis, the Acharya transforms the understanding of the shishya (student) into a reflection of his own understanding. This act is the dharma of the Acharya. The act of dutifully imbibing the lessons is the karma of the shishya. This cycle of transfer of knowledge is the cosmic Rta. Thus, carrying out is the dharma and the karma in accordance with the Rta is the universal cycle of truth that helps both the Acharya and the shishya move closer to oneness with the Brahman. This is a significant role of the atman whereby it (according to monism) can uncover its existence as the Brahman which gets shrouded but the various illusory forces of use prakrit.