The works of Čelčicky are marked by great independence of thought. He rarely cites any authorities, but bases his arguments upon reason and the nature of things. As might be expected, the greater part of his writings treat of religious questions; but he also wrote about history, nature, morals, the rights of society, and the relations of Church and State.
In matters of faith, Čelčicky did not agree with any of the sects of his day. He cared nothing for the power of the keys, did not believe in transubstantiation, nor in purgatory, indulgences, or the invocation of saints. War he called murder on a large scale, and prelates and priests he regarded the satraps of the rulers who supported them in their nefarious persecution of their subjects. Indeed, he regarded all government as an evil that existed only because of the extreme wickedness of man.
Throughout all the teachings of Čelčicky, it is seen that he cared more for correct morals than for correct doctrines; but this morality was to be genuine, arising from real love to God and man. Anything not intrinsically sincere he would have condemned as unmercifully as Žižka.
Brother Gregory.
What made Čelčicky noted in history was not so much his writings as their effect upon others. Among these the most prominent was Gregory, or Brother Gregory, as he is known in the history of the Moravian Brethren.
In 1454, Rokycan, enduring much persecution on account of his unswerving devotion to the new doctrines, sought relief in zealous preaching against the
