Ramanujacharya objected to the Advaitic interpretation of
Upanishadic statements. Advaitins claimed that there was only One — and that was Brahman. The world, according to them, was illusory and it was ignorance that kept Brahman hidden.
Ramanuja raised many objections to this. One of the
examples given by the Advaitins to establish how illusion
can cloak reality is the rope and snake example. A man sees a rope from a distance and thinks it is a snake and is frightened to approach it.
A friend gets close to the rope and assures him that it is a
rope and not a snake. Just as the man mistakes a rope for a
snake, so do we mistake an illusory world for real, went the
argument of the Advaitins.
Ramanuja used the same example to show how even by
common, simple logic, they were wrong, said M.A.
Venkatakrishnan, in a discourse.
If the first man mistakes a rope for a snake and the
second man assures him it is not, that means that they both
know what a snake looks like. Why does the man not mistake the rope for a tiger or a lion? He doesn’t, because a lion or a tiger doesn’t even remotely resemble a snake. But a dangling, coiling rope can look like a snake from a distance.
So he not only knows there is such a thing as a snake, but
he also knows its properties. Without two objects, one
cannot mistake one for the other.
So for a man to mistake the world for Brahman, there
must be a world and its qualities must be known.
Thus Ramanuja argued against the concept that only
Brahman was real and that all else was illusion.