The subject of marriage and insanity is one which is at present beyond practical legislation in this country, but is of immense importance for the social stability and for individual welfare. Though we cannot legislate we have to advise, and our advice is sometimes taken. The lay public as a whole, and the majority of medical men, would at once reply to the question as to the insane ever being allowed to marry in the negative, but I shall contend that a dogmatic statement of this kind is unscientific and unpractical. Such a declaration is taking it for granted that all insanity is alike and is to be treated as of equal value. I shall begin, then, by saying that in my belief certain persons who have suffered from a degree of mental disorder which may be classed as insanity may yet recover and marry with no real increase of risk to their partner or to their children. If I say this, you will next expect me to give examples of the forms of insanity which I should consider as not being of vital importance.