Antonius Thysius the Younger ( 1603 â 25 January 1665), also known as Antonius Thysius filius, Antonius Thysius II, or Anthony Thys, was a Dutch jurist, historian, librarian and rhetorician.
Antonius Thysius the Younger was born in Harderwijk as the son of Antonius Thysius the Elder, who taught theology at the Gymnasium Illustre there. He studied Latin, Greek and Hebrew in Leiden with Daniel Heinsius, Marcus Zuerius van Boxhorn and Constantinus L'Empereur van Oppijck. He then changed his subject to law and graduated as a Doctor of Law on 21 November 1634. On 9 February 1637, he became an associate professor of poetry with special rights. On 21 November 1639, he was also given lectures at the Faculty of Law and on 9 February 1651, he was appointed associate professor of rhetoric.
After becoming assistant at Leiden University Library on 26 August 1653, he became full professor of rhetoric on 8 November 1653 and the fifth librarian of the university library in 1655 as a successor to Daniel Heinsius, in which capacity he reorganised the library. In 1658 he received the honorable appointment of historian of the States of Holland and, after renouncing his special rights, became Associate Professor of Law on 12 November 1663. He was also involved in the management of Leiden University and was rector in 1658/59.
At the end of the tenure of Heinsius as University librarian, the library had descended into chaos. Acquisition had stopped, and its administration was neglected with many books missing, loaned by curators, professors and members of the university council who had possessed a key to the library. Curators then asked young Thysius in 1653 to draw up a new catalogue and rearrange the library. The plutei - subject bookcases with lecterns, chained books and manuscripts - were removed, and bookcases placed against the library walls containing numbered volumes classified according to faculty. Thysius's attempts to oblige all of the printers of the Dutch Republic to send a copy of every new book to the university library failed. However, the rule was locally in Leiden a success. Thysius also managed to purchase books from the estates of scholars like Boxhorn, Claude Saumaise - who had not always been allowed to use the library by Heinsius and had had to buy many books himself - and André Rivet (many heretical Socinian works).