​BURGERSDYK, or Burgersdicius, FRANCIS (1590–1629), Dutch logician, was born at Lier, near Delft, and died at Leiden. After a brilliant career at the university of Leiden, he studied theology at Saumur, where while still very young he became professor of philosophy. After five years he returned to Leiden, where he accepted the chair of logic and moral philosophy, and afterwards that of natural philosophy. His Logic was at one time widely used, and is still valuable. He wrote also Idea Philosophiae Moralis (1644).