Plainly, attention must first be given to straightening and lengthening the curved and shortened spine. This can be done by an expert manipulator who is able to diagnose the erroneous preconceived ideas of the person concerned, and cause the pupil to inhibit them while employing the position of mechanical advantage. And it can be done without asking the pupil to perform what he understands as a single physical act. Moreover, if the correct guiding orders are given to the pupil by the teacher, and the pupil makes no attempt to hold him or herself in the lengthened position, such use of the muscular mechanism will, nevertheless, be brought about as will ensure that the torso is held in a correct position. Formerly, the consciousness in regard to the correct action has been erroneous, a mere delusion, and the muscular mechanisms have worked to pull the body down. The truth of the matter is that in the old morbid conditions which have brought about the curvature the muscles intended by Nature for the correct working of the parts concerned had been put out of action, and the whole purpose of the re-educatory method I advocate is to bring back these muscles into play, not by physical exercises, but by the employment of a position of mechanical advantage and the repetition of the correct inhibiting and guiding mental orders by the pupil, and the correct manipulation and direction by the teacher, until the two psycho-physical factors become an established psycho-physical habit. During this process of re-education, factor (_b_) has not been forgotten. A little consideration will show that any alteration in the spine must necessarily affect the position and working of the ribs. (The analogy of the keel of a boat and the ribs which spring from it may well be held in mind to make clear the following explanation.) It will be seen that as the ribs are held apart by muscular tissues (analogous to the boards of a boat), a bending of the spine will not buckle the ribs unless great force is applied, force sufficient to rupture the muscular tissue. But it is equally evident that there must be some play in the ribs in order that they may adjust themselves to the new position. This play is effected in the human body (and would be effected mechanically in the ribs of a boat, if they possessed sufficient elasticity) by the coming together of the ends of the “false” and “flying” ribs, that is, those lower ribs which are not attached to the bony sternum. This flattening of the curve of the ribs, and the approach of their free ends towards each other, reduces the thoracic cavity, just as in our illustration of the boat its capacity would be reduced if we forcibly narrowed the distance between the thwarts. On the other hand, we see that by increasing the thoracic capacity and so increasing the distance between the ends of these ribs, we are applying a mechanical principle which by a reverse action tends to straighten the spine.