2. We have so far been mainly considering the relations to the production of neuralgia of certain conditions of the central nervous system which indisputably are inherent from birth. Let us now pass quite to the other extreme, and consider a class of momenta which take a decided part in producing many neuralgiæ, but which are altogether accidental and factitious, and cannot be included among the necessary hostile conditions of life. To push the contrast to the utmost, let us inquire first, what amount of influence in the production of neuralgia can be given by such a purely "functional" influence as educational misdirection of intellect and emotion? It is somewhat strange, though every one accepts as a mere truism the maxim that sudden emotional shock may produce almost any degree or variety of nervous disorder, the slower but far surer influence of long-continued mental habit is often practically ignored. It cannot, indeed, be left out of sight as a cause of disorders of the mind itself, nor are there many who would deny that such diseases as cerebral softening are, in a considerable number of cases, the premature ending to a life that has been broken down by harassing work and anxiety. But what is far less appreciated is the tendency of certain unfortunate mental surroundings and modes of mental life to produce a generally neurotic condition, which may express itself in a variety of functional disorders, among which not the least common is neuralgia. I may fairly hope to be acquitted of any predisposition to lay exaggerated stress on this kind of influence in the production of neuralgia, considering all that I have said of the importance of that inevitable cause, the neurotic inheritance, and all that I shall have to say presently as to the effects of a variety of external influences of a totally different kind. But I confess that, with me, the result of close attention given to the pathology of neuralgia has been the ever-growing conviction that, next to the influence of neurotic inheritance, there is no such frequently powerful factor in the construction of the neuralgic habit as mental warp of a certain kind, the product of an unwise education. This work is not intended as a treatise either on religion or psychology, and yet it is impossible for me to avoid some few words that may seem to trench on the province of each: for I believe that there are certain emotional and spiritual and intellectual grooves into which it is only too easy to direct the minds of young children, and which conduct them too often to a condition of general nervous weakness, and not unfrequently to the special miseries of neuralgia. As regards the working of the intellect, it is easier to speak in a free and unembarrassed manner than respecting the other matters. There can be no doubt that, of intellectual work, that sort which exhausts and harasses the nervous system is the forced, the premature, and the unreal kind;