Although condemned harshly by historians for his apparent belief that those identified as witches should be prosecuted, the fact of the matter is that Cotton did not live in Salem and therefore was never directly involved in the famous trials. When he first heard of the problem he offered to take the afflicted girls into his home so that he could try to help. His offer was refused, however. Had it not been, the outcome of the trials might have been quite different. Cotton is credited with much more influence in the trials than he had simply because he made it his business to make everything his business. He had an opinion on everything and did not hesitate to expound on anything.
Cotton Mather is, quite deservedly, mainly remembered as the leading scholar of American Puritanism. He was known to be a controversial figure and wrote prolifically on many subjects (more than 450 books and articles). Magnalia Christi Americana (1702) is a collection of materials and opinions on the church history in New England. Essays to Do Good (1710), a book on morality, influenced Benjamin Franklin.
Like his father, Cotton Mather was a friend of education and science. He also helped found Yale College and was the first American to be elected a fellow of the Royal Society in London. This particular honor affording him the opportunity to become embroiled in yet another controversy. He read a letter written by a Dr. Emanuel Timonious, a medical practitioner in Constantinople in which Timonious describes a method of inoculation for smallpox that had been practiced by Africans for centuries. In questioning his own slave, Onesimus, Cotton learned that he had been so inoculated, and was able to describe the procedure to him! Because New England was in the midst of yet another smallpox epidemic, Cotton wrote to Boston's Dr. Zabdiel Boylston in an effort to convince him of the merits of the smallpox vaccination process. Evidently impressed by Mather's information, Dr. Boylston proceeded to inoculate his 6 year old son and two of his slaves. These were the first to be conducted in America.
In his later years, he wrote: "I am able with little study to write in seven languages. I feast myself with the sweets of all sciences, which the more polite part of mankind ordinarily pretend to. I am entertained with all kinds of histories, ancient and modern. I am no stranger to the curiosities which, by all sorts of learning, are brought to the curious. These intellectual pleasures are far beyond any sensual ones. Nevertheless, all this affords me not so much delight as it does to relieve the distresses of any one poor, mean, miserable neighbor; and much more, to do anything to advance the kingdom of God in the world."
Rev. Cotton Mather died in Boston on February 13, 1727, at the age of 64, and is buried with his father, Increase, in the Mather Tomb at Copps Hill in Boston.