In Vishishtadvaita, the individual souls, also known as jivatmas, play a crucial role in the understanding of the universe and the relationship between the individual and the ultimate reality, Brahman. According to this school of thought, the individual souls are considered to be eternal and distinct from Brahman, but at the same time, they are also believed to be a part of Brahman.

One of the main principles of Vishishtadvaita is the concept of 'Brahman-svarupa,' which means the essential nature of Brahman. This concept states that Brahman is the ultimate reality, and everything in the universe, including the individual souls, is a manifestation of Brahman. Therefore, the individual souls are seen as an integral part of Brahman, and their existence is dependent on Brahman.

The individual souls are believed to be bound by the cycle of birth and death, known as samsara, due to their attachment to worldly desires and actions. However, through the practice of devotion and surrender to Brahman, the individual souls can break free from this cycle and attain unity with Brahman. This is known as moksha, or liberation, and it is considered to be the ultimate goal of human life in Vishishtadvaita.

Furthermore, the individual souls are also seen as having a unique relationship with Brahman. While they are a part of Brahman, they also have their own individual identity and consciousness. This is known as 'jiva-brahma-aikyam,' which means the oneness of the individual soul and Brahman. This concept highlights the idea that even though the individual souls are distinct from Brahman, they are still connected to it and can ultimately merge with it.

In addition to this, the individual souls are also believed to have different levels of consciousness, depending on their level of spiritual evolution. This is known as 'jiva-tattva,' which means the nature of the individual soul. According to Vishishtadvaita, the individual souls can evolve through various stages of consciousness, from being ignorant and attached to worldly desires to being fully aware and devoted to Brahman.

In conclusion, the individual souls play a significant role in Vishishtadvaita, as they are seen as an essential part of the ultimate reality, Brahman. Their existence, relationship, and evolution are all intricately connected to Brahman, and through devotion and surrender, they can attain unity with Brahman and break free from the cycle of samsara.