Grotius was at that time principally employed as an Advocate.

He tells us that to make himself master of the forms of law, he carefully studied the practical part, transcribing precedents of Petitions, Prosecutions, and Defences.

He pleaded his first cause when he was but seventeen, with universal applause, which he maintained whilst he continued at the Bar.

We learn the method he followed in his pleadings from a letter to his son Peter advising him to imitate it.

"That you may not, says he, be embarrassed by the little order observed by those against whom you speak, mind one thing, of which I have found the advantage.