That the laws which disturbed Protestant dissenters should be changed, he argued at length in a pamphlet entitled "A Persuasion to Moderation." Moderation, as he defined it, meant "liberty of conscience to church dissenters;" a cause which, with all humility, he said, he had undertaken to plead against the prejudices of the times. He maintained that toleration was not only a right inherent in religion, but that it was for the political and commercial good of the nation. Repression and persecution, he said, drive men into conspiracies. The importing of religious distinctions into the affairs of state deprives the country of the services of some of its best men. His father, upon the occasion of the first Dutch war, had submitted to the king a list of the ablest sea officers in the kingdom. The striking of the names of nonconformists from this list had "robbed the king at that time of ten men, whose greater knowledge and valour, than any other ten of that fleet, had, in their room, been able to have saved a battle, or perfected a victory." As for a declaration of indulgence, Penn deemed it "the sovereign remedy of the English constitution." That the "tests" should be removed, he urged on James's behalf upon William of Orange, to whom he went in Holland on an informal commission from the king. William, by his marriage with James's daughter, was heir apparent to the throne of England, and his consent was necessary to any serious change of national policy. He insisted on the tests. Theoretically, Penn was right. The ideal state imposes no religious tests; every good citizen, no matter what his private creed may be, is eligible to any office. Practically, Penn was wrong, as William of Orange plainly saw. That prince, as appeared afterwards, was as zealous for religious freedom as was Penn himself; but it was plain to him that as matters stood at that time in England, it was necessary to enforce the tests in order to prevent the rise of an ecclesiastical party whose supremacy would endanger all that Penn desired. Penn, with his stout faith in the king, could not see it. There were times, indeed, when he was perplexed and troubled. "The Lord keep us in this dark day!" he wrote to his steward at Pennsbury. "Be wise, close, respectful to superiors. The king has discharged all Friends by a general pardon, and is courteous, though as to the Church of England, things seem pinching. Several Roman Catholics got much into places in the army, navy, court." Nevertheless, the king's plan, as he understood it, gave assurance of liberty of conscience, and the end of persecution for opinion's sake; and he supported the king.