They corresponded by Letter whilst the President lived: Grotius sent him memoirs[31] for his _History_, and hints relating to the lives and deaths of illustrious men in the United Provinces.
It was a thing infinitely pleasing, and at the same time extremely honorable to a youth between seventeen and eighteen, to be most intimately connected with one of the greatest men of his time, already advanced in years, who filled a post of much eminence, and whom all Europe beheld with admiration.

The friendship and esteem of such a personage is the highest encomium.
M.de Thou gave Grotius, towards the end of his life, sincere proofs of the concern he took in his quiet and welfare.

That great Historian, who had experienced the fiery zeal of some Divines, beheld with pain his friend engaging in controversies which would render him odious to a powerful party.

As if he had foreseen what was soon to happen, he advised him to drop these dangerous disputes.

Grotius wrote him in answer, that he had entered into them only through necessity, to serve his Country and the Church; that he thought himself obliged to obey those who wished he would write on those matters; that, for the rest, he would avoid, for the future, all disputes which were not absolutely necessary.