Philology also includes the study of texts and their history. It includes elements of textual criticism, trying to reconstruct an author's original text based on variant copies of manuscripts. This branch of research arose among Ancient scholars in the 4th century BC Greek-speaking world, who desired to establish a standard text of popular authors for the purposes of both sound interpretation and secure transmission. Since that time, the original principles of textual criticism have been improved and applied to other widely distributed texts such as the Bible. Scholars have tried to reconstruct the original readings of the Bible from the manuscript variants. This method was applied to Classical Studies and to medieval texts as a way to reconstruct the author's original work. The method produced so-called "critical editions", which provided a reconstructed text accompanied by a "critical apparatus", i.e., footnotes that listed the various manuscript variants available, enabling scholars to gain insight into the entire manuscript tradition and argue about the variants.