"In summary it should be understood that all these materialistic philosophers have tried to avoid the Supreme Personality of Godhead by putting forward their own mentally concocted philosophies. However, Vyasadeva, the great sage and incarnation of God head, has thoroughly studied all these philosophical speculations and in answer has compiled the Vedanta-sutra, which establishes the relationship between the living entity and the Supreme Personality of Godhead and the importance of devotional service in ultimately achieving love of Godhead. The verse janmady asya yatah, which appears in the very beginning of Vedanta-sutra, is explained in Vyasadeva's Srimad-Bhagavatam. In Srimad-Bhagavatam Vyasadeva establishes from the very beginning that the supreme source of everything is a cognizant, transcendental person.
The impersonalist tries to explain that the impersonal effulgence of the Supreme Lord (brahmajyoti) is beyond these material modes of nature, but at the same time he tries to establish that the Supreme Personality of Godhead is contaminated by the modes of material nature. The Vedanta-sutra asserts that the Supreme Personality of Godhead is not only transcendental to the material modes of nature but that He also has innumerable transcendental qualities and energies. All these various speculative philosophers are one in denying the existence of the Supreme Lord Visnu, and they are very much enthused to propagate their own theories and be recognized by the people. Unfortunate people become enamored of these atheistic philosophers and consequently can never understand the real nature of the Absolute Truth. It is far better to follow in the footsteps of great souls (mahajanas). According to Srimad-Bhagavatam, there are twelve mahajanas, or great souls, and these are: (1) Brahma, (2) Lord Siva, (3) Narada, (4) Vaivasvata Manu, (5) Kapila (not the atheist, but the original Kapila), (6) the Kumaras, (7) Prahlada, (8) Bhisma, (9) Janaka, (10) Bali, (11) Sukadeva Gosvami and (12) Yamaraja. According to the Mahabharata, there is no point in arguing about the Absolute Truth because there are so many different Vedic scriptures and philosophical understandings that no one philosopher can agree with another. Since everyone is trying to present his own point of view and reject others, it is very difficult to understand the necessity for religious principles. Therefore it is better to follow in the footsteps of the great mahajanas, great souls; then one can achieve the desired success. Lord Caitanya's teachings are just like nectar, and they hold whatever is needed. The best way is to take to this path and follow it."
Teachings of Lord Caitanya, Chapter 21
"Vedanta is the ultimate conclusion of the Absolute Truth (janmady asya yatah), propounded by Vedavyasa. Actually Vedanta philosophy is meant for the devotees because in Bhagavad-gita Lord Krsna says, vedanta-krd veda-vid eva caham: "I am the compiler of Vedanta, and I am the knower of the Vedas." (Bg. 15.15) Vyasadeva is an incarnation of Krsna, and consequently Krsna is the compiler of Vedanta philosophy. Therefore Krsna clearly knows the purport of Vedanta philosophy. As stated in Bhagavad-gita, whoever hears Vedanta philosophy from Krsna is actually aware of the real meaning of Vedanta. The Mayavadis who have called themselves Vedantists do not at all understand the purport of Vedanta philosophy. Not being properly educated, people in general think that Vedanta means the Sankarite interpretation."
Caitanya-caritamrta, Madyam lila 17:96
"Theism is explained completely in the Vedanta-sutra, whereas in other systems of philosophical speculations, practically no mention is given to the ultimate cause of all causes. One can sit on the vyasasana only after being conversant in all systems of philosophy so that one can present fully the theistic views of the Bhagavatam in defiance of all other systems."
Srimad-Bhagavatam 1:1:7 Purport
"The Western philosophers mostly of the Sankhya school have less aquaintance with the Vedanta Darsana and philosophers like Kant, Mill, Aristotle or Schopenhauer etc all belong to either of the above five Darsanas except Vedanta because limited human thinking power cannot go beyond that stage. But Vedanta Darsana is far beyond the limited mental speculation of the human brain conditioned by material nature. Unfortunately Sankara who belonged to the Mayavada school made a misinterpretation of the Vedanta for his own purpose to convert the Buddhists in India.
....Other Acaryas such as Ramanuja, Madhva etc and lately Sri Caitanya--all belong to the original Vedantist school by direct disciplic succession. According to these Acaryas Bhagavad-gita and Srimad-Bhagavatam are, in their original stand, the real commentaries of the Vedanta Sutras. The Mayavadins who do not actually belong to the Vedanta school have overcast a cloud unnecessarily over the Bhagavad-gita and therefore common people are misled by them. In other words they have no entrance in the Vedanta Darsana so to say."
Srila Prabhupada Letter to Mr. Bailey, 10-02-51
"Prakasananda admitted that Sripad Sankaracarya, being very eager to establish his philosophy of monism, took shelter of the Vedanta philosophy and tried to explain it in his own way. The fact is, however, that if one accepts the existence of God, he certainly cannot establish the theory of monism. For this reason Sankaracarya refuted all kinds of Vedic literature that establishes the supremacy of the Personality of Godhead. In various ways, Sankaracarya has tried to refute Vedic literature. Throughout the world, ninety-nine percent of the philosophers following in the footsteps of Sankaracarya refuse to accept the Supreme Personality of Godhead. Instead they try to establish their own opinions. It is typical of mundane philosophers to want to establish their own opinions and refute those of others."
Caitanya-caritamrta, Madyam lila 25:56
"The personified Vedas condemn the impersonal conception as a gross misrepresentation. In the Brahma-samhita, the body of the Supreme Personality of Godhead is described as ananda-cinmaya-rasa. The Supreme Personality of Godhead possesses a spiritual body, not a material body. He can enjoy anything through any part of His body, and therefore He is omnipotent. The limbs of a material body can perform only a particular function, just as hands can hold, but they cannot see or hear. Because the body of the Supreme Personality of Godhead is made of ananda-cinmaya-rasa or sac-cid-ananda-vigraha, He can enjoy anything and do everything with any of His limbs. Acceptance of the spiritual body of the Lord as material is dictated by the tendency to make the Supreme Personality of Godhead equal to the conditioned soul. The conditioned soul has a material body. Therefore, if God also has a material body, then the impersonalistic theory that the Supreme Personality of Godhead and the living entities are one and the same can be very easily propagandized.
....It can be concluded that all the theories of the material philosophers are generated from temporary illusory existence, like the conclusions in a dream. Such conclusions certainly cannot lead us to the Absolute Truth. The Absolute Truth can only be realized through devotional service. As the Lord says in the Bhagavad-gita, bhaktya mam abhijanati, "Only by devotional service can one understand Me." Srila Sridhara Svami has composed a nice verse in this regard, which states, "My dear Lord, let others be engaged in false argument and dry speculation, theorizing upon their great philosophical theses. Let them loiter in the darkness of ignorance and illusion, falsely enjoying as if very learned scholars, although they are without knowledge of the Supreme Personality of Godhead. As far as I am concerned, I wish to be liberated simply by chanting the holy names of the all-beautiful Supreme Personality of Godhead--Madhava, Vamana, Trinayana, Sankarsana, Sripati and Govinda. Simply by chanting His transcendental names let me become free from the contamination of this material existence."
In this way the personified Vedas said, "My dear Lord, when a living entity, by Your grace only, comes to the right conclusion about Your exalted transcendental position, at that time he no longer bothers with the different theories manufactured by the mental speculators or so-called philosophers." This is a reference to the speculative theories of Gautama, Kanada, Patanjali and Kapila (nirisvara)."
Krsna Book, Chapter 87
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.