“So what I intend by the open mind, and in this, I think, Mr. Archer has not fully understood me, is the just use and exercise of conscious reason, a use which is the rare exception to a very delimiting rule. Yours, etc., “F. MATTHIAS ALEXANDER.” To this letter Mr. Archer did not reply, but this brief correspondence covers very fairly, in my opinion, a statement of the popular objection to the “open mind,” and my answer to that objection. Returning now to my own province of therapeutics, I need hardly give any special instance to carry my point. Of late years much attention has been given to the consideration of mental attitude in relation to disease, and although no clearly defined remedy has been advanced, the condition has been diagnosed and defined. The “fixed idea,” hallucination, obsession, are all terms used deliberately to denote a morbid condition, but we have to apply these terms much more widely and grasp the fact that they are applicable to small, disregarded mental habits as well as to the well-defined evils which marked their development. In the case of X, the mental habit which had grown up as the result of postulating, “I can’t draw my lip up before speaking,” was only another aspect of the attitude of A and Z towards the subject of their discussion, and it was precisely similar in kind. The aggregate of these habits is so characteristic in some cases that we see how easily the fallacy arose of assuming an entity for the subconscious self, a self which at the last analysis is made up of these acquired habits and of certain other habits, some of them labelled instincts, the predisposition to which is our birthright, a predisposition inherited from that long chain of ancestors whose origin goes back to the first dim emergence of active life. Fortunately for us there is not a single one of these habits of mind, with their resultant habits of body, which may not be altered by the inculcation of those principles concerning the true poise of the body which I have called the principles of mechanical advantage,[13] used in co-operation with an understanding of the inhibitory and volitional powers of the objective mind, by which means these deterrent habits can be raised to conscious control. The false pose and carriage of the body, the incorrect and laboured habits of breathing that are the cause of many troubles besides the obvious ill effects on the lungs and heart, the degeneration of the muscular system, the partial failure of many vital organs, the morbid fatty conditions that destroy the semblance of men and women to human beings,—all these things and many more that combine to cause debility, disease, and death, are the result of incorrect habits of mind and body, all of which may be changed into correct and beneficial habits if once we can clear away that first impeding habit of thought which stands between us and