Alsted has been called ‘one of the most important encyclopedists of all time’. He was a prolific writer, and his Encyclopaedia (1630) long had a high reputation. It was noticed that sedulitas, meaning “hard work” in Latin, was an anagram of Alstedius. It was preceded by shorter works, including the 1608 Encyclopaedia cursus philosophici. His major encyclopedia of 1630, the Encyclopaedia, Septem Tomis Distincta, was divided into 35 books, and had 48 synoptical tables as well as an index.