( Story told by Swami Vivekananda )
About fourteen hundred years before Christ, there flourished in India a great philosopher, Patanjali by name. He collected all the facts, evidences, and researches in psychology and took advantage of all the experiences accumulated in the past. Remember, this world is very old; it was not created only two or three thousand years ago. It is taught here in the West that society began eighteen hundred years ago, with the New Testament. Before that there was no society. That may be true with regard to the West, but it is not true as regards the whole world.
Often, while I was lecturing in London, a very intellectual and intelligent friend of mine would argue with me, and one day after using all his weapons against me, he suddenly exclaimed, “But why did not your Rishis come to England to teach us?”
I replied, “Because there was no England to come to. Would they preach to the forests?”
“Fifty years ago,” said Ingersoll to me, “you would have been hanged in this country if you had come to preach. You would have been burnt alive or you would have been stoned out of the villages.”
So there is nothing unreasonable in the supposition that civilisation existed fourteen hundred years before Christ.
Source : The Complete Works of Swami Vivekananda/Volume 2/Hints on Practical Spirituality