The debate over clerical marriage was a bitter one in the English Protestant Reformation, revealing different views of human nature. For Protestants, the idea that lifelong celibacy could be required of priests was unnatural and harmful. For Catholics, celibacy and chastity was a vow that men could make freely of their own will. This debate over human nature and free will would dominate the clerical marriage controversy during the Reformation in the mid-Tudor period, from the 1530s to the 1550s. The study of clerical marriage is too-often treated in a vacuum, as a theological issue. In fact, clerical marriage debate was, at its basis, as much biological as it was political or ideological. These English theologians attended Cambridge together and knew each other well, but wound up on opposite sides of the debate. This thesis will analyze works by Protestants such as George Joye, John Ponet, and John Hooper, as well as a book written by the Catholic Stephen Gardiner. Joye and Ponet argue that it was human nature to desire to get married and have children. Hooper extends the argument of human nature to encompass God's will, claiming that God would not have created human nature to contradict God's law. In contrast, Gardiner argues that humans had free will, directly contradicting the Protestants' claims. When discussed in their entirety, these works reveal an entirely different analysis of clerical marriage, one that ties into the much larger debate of human nature and free will.