In his book, A Critical Survey of Indian Philosophy, by Dr. Prof. Chandradhar Sharma, addresses these attacks on Advaita. Venkatanatha (also known as Vedantadeshika) (a follower of Ramanuja) in his Shatadusani, levels 66 charges on Advaita. Prof. Sharma addresses these in the following manner.
Prof. Sharma writes (pp 361-2):
…[charge] If Brahman is a qualityless homogenous entity, the word ‘Brahman’ cannot denote it either in a primary sense or in an implied sense (laksana) and hence it becomes useless.
[answer] Venkatanatha forgets that words, according to Shankara himself, can never denote the Absolute which can be realized only be direct spiritual vision. Language and thought would become insignificant only when they are transcended, not before. As long as we are in the phenomenal sphere, they are the instruments available to us and we have to work with them however defective they may be.
Further on page 365:
…Ramanuja is credited with reconciling the demands of philosophical thinking with those of religious feeling. These people do justice to Ramanuja but injustice to Shankara. They forget the important fact that neither Shankara overlooked the demands of religious feeling nor could Ramanuja satisfactorily harmonize religious feeling with logical thinking. To dub Shankara’s Absolute as a bare identity is to betray ignorance even of the significant name his philosophy bears—‘Advaita’—which means not ‘bare identity’ but ‘denial of ultimate difference’. He who imagines that Shankara’s position means complete denial of this world, of the souls, of action, of philosophy, of religion and even of God, may know anything but Shankara Vedanta. The veteran idealist of England, T. H. Green has rightly remarked: ‘the fact that there is a real external world—is one which no philosophy disputes’.
And on pp 366-8 he says:
Let no man stand up and say that Shankara’s philosophy is the philosophy of bare identity or that it lacks religious fervor. One has only to turn to the practical life of Shankara which has always been a paradox to those who have misunderstood or half-understood the teachings of the great Acharya. Shankara would gladly say with Bradley that ‘the man who demands a reality more solid than that of the religious consciousness knows not what he seeks.’ Bosanquet, a great idealist, has said in connection with realism-idealism controversy: ‘Certainly for myself if an idealist were to tell me that a chair is really not what we commonly take it to be, but something altogether different, I should be tempted to reply in language below the dignity of the controversy.’ A follower of Shankara might be tempted to reply similarly to one who tells him that Shankara’s philosophy advocates bare identity or that it is devoid of religious fervor or that it denies the world outright. Or perhaps he would not. He would simply remember the words of Gaudapada: It is only the dualists who in order to establish their respective views fight with one another; Advaitin fights with none. (Karika III.17)
Let us try to do justice to both Shankara and Ramanuja. It has been already pointed out that Ramanuja was much influenced by the Alvars and the Archaryas and by the bhedabhedadvadins who preceded him. Indeed his main task was to combine the Pancharatra theism with the Upanishadic Absolutism. He wanted to find philosophical justification for the Vaisnava theism in the Prasthana-traya of the Vedanta and thus tried to harmonize the demands of religious feeling with logical thinking. But he confined himself to justify Pancharatra theism by means of Upanishadic Absolutism. It is one thing to combine Philosophy with Religion, but quite another thing to one particular philosophical doctrine with a particular religious creed. Shankara has attempted the former, while Ramanuja has attempted the latter. For Shankara, the only scriptures were the Vedantic texts and he interpreted them so as to harmonize logical thinking with religious feeling. For Ramanuja, the scriptures included besides the Vedantic texts, the Vaisnava Puranas, the Pancharatra-Agama and the Tamil Prabandham, and his main task was to prove that the doctrines of the Vaisnava theism are in conformity with the Vedantic tradition. There are some doctrines of the Vaisnava theism which can be harmonized with the Vedantic Absolutism, but not all. And if, therefore, Ramanuja failed, his failure is due not to his personal incapacity but due to the very nature of the difficult task he undertook to perform. It must be admitted without reservation and in all fairness to Ramanuja that no one else could have done it better. He has given us the best type of monotheism pregnant with immanentism. He has emphasized the religious side but not at the cost of the philosophical…Ramanuja’s position is essentially similar to the position of Shankara viewed from the practical or phenomenal (vyavahara) standpoint. For all practical purposes Shankara maintains the the reality of all secular and Vedic acts. From this standpoint the entire universe including the material world and the individual souls is as real as it can be. And though the highest reality is the indeterminate Brahman, yet the highest conception open to us, finite intellectual beings, is Ishvara and Ishvara alone. Though the universe is only a vivarta or an appearance of Brahman, yet as long as it lasts it is as good as real. Sarvajnatma-Muni is right in holding that Parinamavada (the position of Ramanuja) is an earlier stage of Vivartavada (the position of Shankara) and that the two are not opposed.
Let us now turn to the diacritical unfolding of the inherent contradictions in the philosophy of Ramanuja. Ramanuja has failed to express the relation between the universe and God. According to him matter, souls and God are the three realities and all the three make up the Absolute. And yet he identifies the Absolute with God who is only one of the three realities. God is the underlying substratum of matter and souls which are said to be His attributes. But if they are His attributes or modes, how can they be as real as God? The criticism of Spinoza leveled against Descartes that matter and souls cannot be called ‘substances’ if they are dependent on God can be very well leveled against Ramanuja also. Ramanuja abolishes the distinction between attributes and modes and though he explicitly maintains the distinctions between attributes and substance, yet he implicitly undermines this distinction also. According to him a thing can be a substance as well as an attribute. The distinction is relative. Though matter and souls are substances in themselves yet in relation to God they are merely His attributes. The very definition of ‘substance’ is that it has an independent existence. Ramanuja undermines this definition when he says that independence does not constitute the essence of substance, that a thing may be dependent and yet a substance. This is logically most unsatisfactory. If matter and souls are absolutely dependent on God, how can they be as real as God? Shankara defines the real as that which has independent existence for all times and tells us that Brahman alone is real. But he does not deny the existence of matter and souls. The dilemma before Ramanuja is this—either maintain the relative existence of matter and souls or abolish your Absolutism. And Ramanuja is prepared to do neither. Loyalty to the Upanishads makes him cling to Absolutism while sympathy for Vaisnavism makes him recognize ultimate distinctions. Thus Vishistadvaita is a house divided against itself…Ramanuja, therefore, has not been unable to solve the problem of the relation between the universe and the Absolute. He has stated that the universe is organically related to the Absolute, that it is the body of God, that though it has a right to exist separately it is not external to God who is All-inclusive, that identity is always qualified by difference. But he fails to explain his position further. The relation between the universe and God is not pure identity, for the very notion is a pseudo-concept, a bare abstraction. This relation is not that of difference for pure difference also is equally an abstraction. Difference belongs to and cannot remain separate from identity. This relation is not that of identity-and-difference (bhedabheda) for it is self-contradictory. Both identity and difference like light and darkness cannot belong to the same thing in the same sense…
And on page 370:
…Verily then, Ramanuja’s Absolute is Shankara’s Brahman bound to this world, while Shankara’s Absolute is Ramanuja’s Ishvara liberated from this world, Ramanuja cannot sustain the distinction between God’s body and soul. One cannot, as Shankara says, keep half a hen for cooking and reserve another half for laying eggs. It cannot be logically maintained that the soul of God is changeless and perfect while His body suffers change and imperfections.
Again, Ramanuja tries to combine the Upanishadic Absolutism with the personal Theism of the Pancharatras. Here also he fails. If God is the immanent soul of the universe, how can He at the same time be a transcendent Person living in Vaikuntha with His consort Laksmi and attended upon by the nitya and the mukha souls? As Dr. Radhakrishnan says: “Ramanuja’s beautiful stories of the other world, which he narrates with the confidence of one who had personally assisted at the origination of the world, carry no conviction…”…The distinction between the Prakrti ot Lilavibhuti and Shuddhasattva or Nityavibhuti is arbitrary. If the body of God is made up of Prakrti and souls, what is the necessity of assuming Nityavibhuti as the stuff where God dwells and which constitute the body of God? Moreover, when sattva, rajas and tamas are the gunas of Prakrti and as such inseparable from it how can sattva be abstracted and made to form Nityavibhuti which limits Prakrti from above?
The distinction between the nitya and the mukta souls is also arbitrary. Souls may be either bound or liberated. What is the necessity of maintaining the third variety?
…Though Ramanuja admits the self as the self-conscious subject, yet he is unable to shake off the Nyaya-Vaishesika influence that the self is a substance possessing the quality of consciousness…
This is a sample of some of the arguments made, but is not complete as the arguments are extensive.
I would conclude this answer with Swami Vireswarananda’s comments at the end of his Introduction to his translation of Ramanuja’s Sri-Bhasya. He says:
The Upanishads, as already stated at the very beginning, do not teach any particular doctrine. They teach various doctrines suited to different people at different stages of spiritual evolution. They are not contradictory, but based on the principle of individual fitness for receiving a truth (Adhikaribheda). The aspirants are taken step by step to the ultimate truth, from dualism to qualified monism and finally to monism. “That thou Art” is the last word of the Upanishads in religion. The Brahma-Sutras also are as comprehensive as the Upanishads and contain references to these various stages. Hence, commentators, when they claim that their commentary alone is correct, do not reflect Badarayana’s view truly.