Final answer:
Crusoe's mastery over the mutineers is derived from fear and torture.
Step-by-step explanation:
In Daniel Defoe's novel 'Robinson Crusoe,' the source of Crusoe's mastery over the mutineers when they first encounter one another is fear and torture. When the mutineers arrive on the island, Crusoe uses his superior knowledge and physical control to intimidate and overpower them. He instills fear in them through his actions and demonstrates his power by subjecting them to torture when necessary.