I protest against this, not only in the name of justice, but in the name of common sense.  It cannot be possible that generations of dealing with immature minds should have left no residuum of effective practice.  The very principle of progress by trial and error will inevitably mean that certain practices that are possible and helpful and effective are perpetuated, and that certain other processes that are ineffective and wasteful are eliminated.  To repudiate all this is the height of folly.  If the history of progress shows us anything, it shows us that progress is not made by repudiating the lessons of experience.  Theory is the last word, not the first.  Theory should explain:  it should take successful practice and find out what principles condition its efficiency; and if these principles are inconsistent with those heretofore held, it is the theory that should be modified to suit the facts, not the facts to suit the theory.

My opponents may point to medicine as a possible example of the opposite procedure.  And yet if there is anything that the history of medical science demonstrates, it is that the first cues to new discoveries were made in the field of practice.  Lymph therapy, which is one of the triumphs of modern medicine, was discovered empirically.  It was an accident of practice, a blind procedure of trial and success that led to Jenner’s discovery of the virtues of vaccination.  A century passed before theory adequately explained the phenomenon, and opened the way to those wider applications of the principle that have done so much to reduce the ravages of disease.

The value of theory, I repeat, is to explain successful practice and to generalize experience in broad and comprehensive principles which can be easily held in mind, and from which inferences for further new and effective practices may be derived.  We have a small body of sound principles in education to-day,—­a body of principles that are thoroughly consistent with successful practice.  But the sort of principles that are put forth as the last words of educational theory are often far from sound.  Personally I firmly believe that a vast amount of damage is being done to children by the application of fallacious principles which, because they emanate from high authority, obtain an artificial validity in the minds of teachers in service.

I cannot understand why, when an educational experiment fails lamentably, it is not rejected as a failure.  And yet you and I know a number of instances where certain educational experiments that have undeniably reversed the hypotheses of those who initiated them are excused on the ground that conditions were not favorable.  That, it seems to me, should tell the whole story, for precisely what we need in educational practice is a body of doctrine that will work where conditions are unfavorable.  We are told that the successful application of mooted theories depends upon the proper kind of teachers.  I maintain