It is a well-recognised fact that persons suffering from many forms of beginning mental disease are likely to be affected by an exaggeration of religious sentiment. An unaccountable increase in piety is sometimes the first warning of approaching mental deterioration. It is not hard to understand why this should be, since religious feelings occupy so prominent a place in the minds of the majority of people, and the removal of proper control over mental operations of all kinds leads to an exaggeration, especially of those that have meant most for the individual before. Supposed religious vocations, especially when of sudden development, are sometimes no more than an index of disturbed mentality. Every confessor of lengthy experience has had some examples of this. This makes it important that clergymen should have a knowledge of at least the first principles on which the diagnosis of mental diseases is made. Superiors of religious communities, and especially those that have to decide as to the suitability of those applying for entrance to, or already in probation for, the religious life, need even more than others a definite knowledge of the beginning symptoms of the various mental diseases, and of the types of individuals that are most prone to suffer from them. Besides, confessors and religious friends and advisers often gain the confidence of the mentally diseased much more fully than any one else. It is to them especially that the earliest symptoms of beginning mental disturbance are liable to be first manifested. After all, a pastor's and a {212} confessor's duty is bound up with the welfare of his spiritual children in every sense; and it would be supremely serviceable to the patients themselves and to their friends, if these earliest symptoms could be recognised and properly appreciated, and due warning thus given of the approach of further mental deterioration. The mental diseases that are of special interest in this respect are the so-called idiopathic insanities. Idiopathic is a word we medical men use to conceal our ignorance of the cause of disease. Idiopathic diseases are those that have come of themselves, that is, without ascertainable cause. As a matter of fact, the most important group of mental diseases develop without presenting any alteration of the brain substance, so far as can be detected by our present-day methods of examination. The initial symptoms of these diseases, then, are of great importance, and not readily recognisable unless looked for especially. There is no physical change to attract attention, and the change of disposition and mental condition is often insidious and only to be recognised by some one who is in the confidence of the patient. It is in these idiopathic insanities, then, that the careful observation of the clergyman is of special significance. Needless to say, powers of observation to be of service must be trained.