In 1645 Johan and his elder brother Cornelius visited France, Italy, Switzerland and England, then on his return Johan lived at The Hague as an advocate.
Sa 1645 Johan at ng kanyang kuya Cornelius binisita France, Italya, sa Swisa at Inglatera, at pagkatapos ay bumalik sa kanyang Johan nanirahan sa Ang Hague bilang isang tagapagtaguyod.