Theodorus Johannes "Dirk" Graswinckel[1] (1 October 1600 – 12 October 1666[2]) was a Dutch jurist, a significant writer on the freedom of the seas. He was a controversialist, who also rose to a high legal position (Fiscal of Holland) where he advised Descartes.[3] He was a cousin and pupil of Grotius.[4] He was also a poet and translator of Thomas à Kempis.[5]