In the history of the book, indexes emerged as a result of a number of developments in paratexts and organization. The earliest examples of this device varied significantly in layout, organization, and textual form. While various kinds of tables of contents are attested in the ancient world, the index is a much later innovation. The earliest use of indexes is found in legal and then scholastic and patristic texts in continental Europe; they were particularly useful for university students and preachers. Indexes served as aids to help them navigate the growing corpus of legal and theological compilations and commentaries. However, their format and function were variable: the manuscript evidence shows a great degree of experimentation, combining alphabetic, vocalic, and systematic orders of arrangement. In the early modern period, with increasing anxieties about how to organize and manage information, treatises instructed readers how to compile an index. In turn, from the 16th century and well into the 18th, writers cautioned against an excessive reliance on these book aids in lieu of reading the whole books and lampooned so-called “index learning.” The use of indexes in Greek, Hebrew, and Islamic book culture only began in earnest in the early modern period.
