Teke frå Wikiquote som oppgav George MacDonald and His Wife av Greville MacDonald, sonen til MacDonald.
«I firmly believe people have hitherto been a great deal too much taken up about doctrine and far too little about practice. The word doctrine, as used in the Bible, means teaching of duty, not theory. I preached a sermon about this. We are far too anxious to be definite and to have finished, well-polished, sharp-edged systems - forgetting that the more perfect a theory about the infinite, the surer it is to be wrong, the more impossible it is to be right.»