Do you think Columbus purposefully lied about discovering Asia?
It is known that Columbus claimed on his deathbed that he believed he had fulfilled his charter and had found a route to Asia, proving his navigational skills and calculations to be correct.
However, Historian Alfred Crosby Jr, in his book "The Columbian Exchange," argues that Columbus must have known he was not in Asia and doubled down on his lie to preserve what little of his reputation he had left near the end of his life.
Crosby argues that there are such blatant lies or inaccuracies in Columbus's letters to the monarchy of Spain and in his journals, which he knew would be published, that he must have known he was not where he claimed to be. Columbus describes hearing familiar bird songs and species of foul from the eastern Mediterranean, birds, and animals that don't even exist in the parts of Asia he claimed to have landed. Crosby argues that he must have manipulated the facts to fit his cause and make the lands he discovered more "familiar" to his audience. In addition, he makes the legal and financial argument that if Columbus did not make it to Asia as he was chartered, he would not have been financed again by Spain.
All of this mounts severe pressure to convince people of your success, even if you have discovered two vast continents of material wealth in your failure. In addition, Crosby explains that Columbus's voyages do not being to be profitable until the second, third, and fourth journeys, during which he brings back gold, silver, coral, cotton, and detailed information about the fertility of the land—reinforcing his desire to prove his success early on to maintain proper financing.
However, Crosby does concede that due to limited primary sources, as most are from Columbus himself and his perspective and bias, Columbus may have believed his miscalculations as he discovered land approximately near the distances he predicted. And the lack of detailed European maps of the Asian islands near Japan and China would have made it difficult to disprove his theory, even as he interacted with (and Spain continued to interact with) new indigenous peoples of Central and South America.1