The polemical works of Lucas are very numerous, and are directed indifferently against all those who did not accept the doctrine of the Unity as expounded by him. His controversies with Luther have already been mentioned. A work of Lucas's is directed against Zwingli, whose teaching had also penetrated into Bohemia. He also engaged in a theological controversy with "Wolfgang, the barefooted friar." Wolfgang, one of the earlier champions of the Church of Rome, played a curious part in the great theological controversy that absorbed almost the whole intellectual activity of Bohemia during two centuries. I shall again refer to him. Another controversial book of Lucas's directed against Brother Kalenec, a member of the "small party" in the Unity, is interesting as containing the author's opinion on Chelčicky, whose memory was naturally very popular with the smaller and more retrograde fraction of the Unity. Lucas writes: "You take refuge with Peter of Chelčic, and recommend to others his books, such as the _Net of Faith_. I, who have read and copied out many of his books before I joined the brethren, will say that in many matters he thought wrongly, and in a manner contrary to Scripture, and that he wrote obscurely and without moderation. I have also heard from those brethren that were with him much that was not praiseworthy, particularly that he was very irritable and vindictive. Thus, having fallen out with a priest, he would not forgive him till his death; so that priest himself told me. And he (Chelčicky) unjustly defamed the Taborite priests, particularly as regards their teaching on the sacrament." A year before his death, Brother Lucas again returned to his favourite subject, the identification of the Unity with the primitive Church, in his treatise _On the Origin of the Unity_. Dealing with the manner in which the consciousness of the corruption of the Church reached Bohemia, Lucas writes: "The movement began through the Waldenses in England, where Wycliffe was the king's chaplain, but only read mass. And a Waldensian with whom he was acquainted said to him that he only fulfilled half the duty of his office, because he did not preach; and he proved this from Scripture.... Then of those who at that time (in England) suffered much adversity and martyrdom, some went to other countries, and particularly to Dresden, and thence some of them afterwards proceeded to Bohemia," Though unhistorical, this account is curious as containing what was probably a very old tradition. Lucas here, as was frequently the case with Bohemian writers of his time, describes as "Waldenses" all early opponents of the Church of Rome.