The problem of establishing the Latin text has been resolved, thanks to the work of dedicated German scholars. In 1928, Professor Gerhard Kallen agreed to prepare a critical Latin edition under the auspices of the Heidelberg Academy of Sciences. Books Ⅰ and Ⅱ were published in 1939 but the publication of Book Ⅲ was delayed by World War Ⅱ and it only appeared in 1959. In 1964 and 1965 Books Ⅰ and Ⅱ were reissued with a critical apparatus that incorporated more recent scholarship, and in 1968, on Gerhard Kallen''''s eighty-fourth birthday, a complete set ofindices to the entire work was published.