[8] He did not at once adopt the Quaker dress, and continued for some time to wear a sword. When this non-compliance with Quaker customs was reported to George Fox, it is said that he simply replied, "let him wear it as long as he can." He mentioned years afterwards how the peculiar garb was a stumbling-block to some, "It telleth tales, it is blowing a trumpet and visibly crossing the world; and this the fear of man cannot abide" (_Travels_, p. 121). Probably this very fact commended the peculiarity to his bold and decided spirit. Henceforth William Penn's time and strength were given to Quakerism. There was neither hesitation nor half-heartedness. The welfare, work, and sufferings of Friends he made his own. He wrote and preached with untiring energy, and suffered, counting it joy. Though turned out of doors by his father, he was not allowed to want. His mother privately supplied his needs to the utmost of her ability, and what she could not do was made up by several kind friends. The situation was painful in the extreme; separated from home and parents, his father grieved and mortified at his conduct. He tells pathetically afterwards of "the bitter mockings and scornings that fell upon me, the displeasure of my parents, the invectiveness and cruelty of the priests, the strangeness of all my companions, what a sign and wonder they made of me." But his conscience approved of the line he had adopted, and his resolute nature was troubled by no waverings. He set himself earnestly to do his duty. He united himself closely to the Friends, and took up his pen on their behalf. His first work was entitled "Truth exalted." "The Guide Mistaken," soon followed. It was a reply to "A Guide to the true Religion," in which the Quakers were treated with great severity. Shortly afterwards he was drawn into a public discussion with the Rev. Thomas Vincent, a Presbyterian minister in Spitalfields. Some of his congregation having become converts to Quakerism, Vincent said some slanderous things about the Friends. So George Whitehead and Wm. Penn waited upon him, and insisted that as he had publicly misrepresented them, he was bound in fairness to give them an opportunity publicly to set themselves right. After some demur, Vincent agreed to meet them in his own chapel on a certain day. The discussion lasted until midnight, and turned principally upon the question of the Trinity. Friends have always asserted that the doctrine, as taught by the orthodox, is an attempt to explain the inexplicable, and goes beyond what is revealed in the Scriptures. This contention in their early days cost them much reproach; now the chief remnant of it is the annoyance of having their authors, especially Penn, quoted as believers in the Unitarianism of to-day.