Final answer:
Grotius argued for the concept of freedom of the seas in his book Mare Liberum, advocating for unrestricted access to the seas for all nations.
Step-by-step explanation:
In his book Mare Liberum, Grotius argued for the concept of freedom of the seas. He contended that the seas were a common property and should be accessible to all nations without any restrictions or dominance from a single nation. Grotius believed that this concept of mare liberum would promote peaceful trade and collaboration among nations.