Psychopathy
In the historical work, Batavia's Graveyard, which analyzes the incident in more detail than ever before based on research in Dutch archives, amongst other sources, author Mike Dash theorizes that Cornelisz was almost certainly a psychopath. This is shown by his often erratic behavior on the islands, his unattainable dreams of setting up a personal kingdom in the islands, and his complete assurance that he could do no wrong and that God himself inspired all of his deeds. This ties in with the heretical ideas he had picked up during his acquaintance with the controversial painter Johannes van der Beeck (also known as Torrentius).
Read more about this topic: Jeronimus Cornelisz