Several distinct component are constitutive of what we now know to be Viśiṣṭādvaita Vedānta and are not present at the time of Rāmānuja:

1. 1. The inclusion of the Āḻvār’s theology in Viśiṣṭādvaita Vedānta
2. 2. The Pāñcarātra orientation of both subschools of Viśiṣṭādvaita Vedānta
3. 3. The two sub-schools
4. 4. The Vedāntisation of Viśiṣṭādvaita Vedānta
5. 5. The impact of other schools

The two sub-schools
The discussion on Pāñcarātra (which you can find in the first part of this post, here) suggests a more general problem regarding the origin of the two “subschools” of Viśiṣṭādvaita Vedānta. Western scholars initially described them by projecting retrospectively the split into Vaṭakalai and Teṅkalai to more ancient times (Lester attributes it already to ”less than 150 years after Rāmānuja’s death”, 1976, p. 150) and even called the split a ”schism” (Kirchentrennung, Otto 1917, p. 6), thus betraying a tendency to re-read it through the lenses of the history of Christian theology. Raman, among others, has shown how the split occurred only much later (around the 17th c., see Raman 2007). Mumme (1988) suggested that the two sub-schools have a distinct prehistory, linked to the two centers of Śrīraṅgam (for the later Teṅkalai) and Kañcī (for the later Vaṭakalai), both originating from Rāmānuja’s teaching. The hypothesis could be led further until the consequence that there was never a unity which then split into two and that the two distinct currents, rather, were brought together by the converging efforts of some theologians (see this post) and by the fact of sharing a religious background.

The Vedāntisation of the Viśiṣṭādvaita Vedānta
Who is responsible for the Vedāntisation of the school? Rāmānuja is a clearly Vedāntic author, whereas Yāmuna is not, but was the turn determined only by the former?

The impact of other schools

Rāmānuja is first and foremost a Vedāntic author, but his position towards Pūrva Mīmāṃsā is much more inclusive than Śaṅkara’s one, something which could be due to his choice or to Śaṅkara’s peculiar choice to exclude Pūrva Mīmāṃsā (a question which is difficult to solve, given that no other early Vedāntic commentary is preserved).
Apart from Vedānta, the most obvious candidate would be Nyāya, which in fact did influence Nāthamuni (judging from the title of one of his lost texts) and certainly Yāmuna’s first adherence to the idea of inferring God’s existence and his life-long adherence to the idea of inferring the validity of the Pāñcarātra Sacred Texts from the fact that they have a reliable author, namely God. The confrontation with Nyāya changed by the time of Veṅkaṭanātha, who authored a Purification of Nyāya (Nyāyapariśuddhi).

How and why did Viśiṣṭādvaita Vedānta develop the way it did?

This post is the second part of a revised summary of the introduction I held at my panel at the World Sanskrit Conference. For the first part, see here. For a pdf of my presentation, see here. For a summary of the panel in general, see here.