It may indeed be urged that his failure to bequeath to posterity any regular guide to the spiritual life was due to lack of time, that his active and unremitting struggle with his opponents left him no leisure, and, in point of fact, it is quite true that his controversy did deprive him of the requisite freedom and peace of mind. It may also be allowed that no one man can do everything and that Luther had not the methodical mind needed for such a task, which, in his case, was rendered doubly hard by his revolution in doctrine. The main ground, however, is that there were too many divergent elements in his moral teaching which it was impossible to harmonize; so much in it was false and awry that no logical combination of the whole was possible. Hence his readiness to invoke the theory, which really sprung from the very depths of his ethics, viz. that the true Christian has no need of rules because everything he has to do is the natural outcome of faith. In his “Sermon von den guten Wercken” (1520), he expressed this in a way that could not fail to find a following, though it could hardly be described as in the interests of moral effort. Each one must take as his first rule of conduct, not on any account to bind himself, but to keep himself free from all troublesome laws. The very title of the tract in question, so frequently reprinted during Luther’s lifetime, would have led people to expect to find in it his practical views on ethics. Characteristically enough, instead of attempting to define the exact nature and value of moral effort, Luther penned what, in reality, was merely an appendix to his new doctrine on faith. He himself, in his dedication of it to Duke Johann of Saxony, admits this of the first and principal part: “Here I have striven to show how we must exercise and make use of faith in all our good works and consider it as the chiefest of works. If God allows me I shall at some other time deal with faith itself, how we must each day pray and speak it.”[303] As, however, no other of Luther’s writings contains so many elements of moral teaching drawn from his theology, some further remarks on it may here be in place, especially as he himself set such store on the sermon, that, while engaged on it, referring evidently to the first part, he wrote to Spalatin, that, in his opinion it “would be the best thing he had yet published.”[304] Köstlin felt justified in saying: “The whole sermon may be termed the Reformer’s first exposition and vindication of the Evangelical teaching on morals.”[305]