The quote you are referring to was originally written as follows:
'Those who cannot remember the past are condemned to repeat it'----George Santayana From his work; Life of Reason, Reason in Common Sense 1905. It should be noted that William Shirer included the quote as an epigraph in his literary work The Rise and Fall of the Third Reich in 1959. The book was extremely popular when it was published and as such could have lended a hand in the popularity of the quote.
The quote “Those who forget history are condemned to repeat it” is attributed to the American philosopher George Santayana and it can be accurately quoted as “Those who cannot remember the past are condemned to repeat it” as stated in his work, The Life of Reason: Reason in Common Sense. His work speaks mostly about the role of rationality in moral philosophy and general ethics. The philosopher was born in Madrid, Spain and lived there in his early years before relocating to Boston. His early life contributed much to his philosophical works. He loved poetry and obtained philosophical mentorship from William James and Josiah Royce who were famous Harvard philosophers. He went ahead to teach philosophy in Harvard before leaving for Europe. The Life of Reason was done as a series which included Reason in Common Sense (which features the famous quote), Reason in Society, Reason in Religion, Reason in Art and Reason in Science.
This perticular saying has ,many times, been changed over the time. However, the meaning remained intact: we should not forget and repeat the mistakes of the past.
It was for the first time used by Mr George Santayana, a Spanish born American author of the late nineteenth & early twentieth centuries,in his book Life of Reason,Reason in common sense, Scribner`s 1905 Page 284.However, the actual words are the followings:``Those who can not remember the past are condemned to repeat it.`` http://answers.google.com/answers/threadview?id=495329