The Vaishnavite Acharya Vedanta Desika wrote a Sandesam (message) titled, ‘Tattva Sandesam’, for the benefit of a King. Herein, Vedanta Desika elucidates the nature of the atma and the nature of Parabrahma and explains the basic tenets of Visishtadvaita, said M.K. Srinivasan in a discourse. Desika says the Supreme One is the Master of the Universe. He is the One in control of cetanas (sentient) and acetanas (non-sentient). Nothing can happen without His will. Both cetanas and acetanas constitute His body. The fruits of our karmas belong to Him. While we have to do our karmas (duties) as prescribed, we cannot enjoy the fruits thereof.
Among the cetanas are three categories. The Nitya cetanas have no samsaric ties and are always in Sri Vaikuntha, serving Him. The other two are Bhadda cetanas and Mukta cetanas. The Bhadda cetanas are the ones caught in the coils of samsara, who are there because they are reaping the effects of their past actions. The Mukta cetanas are those who, after suffering in samsara because of their past Karma, surrender to Him, and are thus liberated.
The Jivatma is the abode of gnana. The Paramatma too is the abode of gnana. But the Paramatma is the Master and the Jivatma the servant. In the Tattva Sandesam, after explaining the Tattvas, Desika tells the king that his behaviour should be pleasing to righteous men. He should be fearful of offending those who are devoted to Lord Narayana. As for those who are interested only in worldly pleasures, he should think of such people as equal to mere blades of grass. In other words, he must not think of them as important at all. He must place his trust in the Lord to whom he should surrender. The Lord, who is forever seen with Goddess Mahalakshmi, is merciful, and this should be always kept in mind. Having surrendered to the Lord, a man should no longer worry about anything. He should spend his life in contemplation of the Lord and must await His mercy like the cataka bird. This legendary bird is said to wait for the rains to fall, for it will drink no other water, but will receive the rainwater directly into its beak. So must we look up to Him and wait for His grace to fall on us.