6. These explanations are not mere abstractions, gentlemen, or mere philosophical speculations. True, my subject is philosophical; but it is the philosophy of every-day life; we are dealing with live issues which give rise to the gravest discussions of your medical journals; issues on which practically depend the lives of thousands of human beings every year, issues which regard physicians more than any other class of men, and for the proper consideration of which Doctors are responsible to their conscience, to human society, and to their God. To show you how we are dealing with present live issues, let me give you an example of a case in point. In the "Medical Record," an estimable weekly, now in almost the fiftieth year of its existence, there was lately carried on a lengthy and, in some of its parts, a learned discussion, regarding the truth of the principles which I have just now explained, namely, the intrinsic difference between right and wrong, independently of the ruling of law courts and of any human legislation. The subject of the discussion was the lawfulness in any case at all of performing craniotomy, or of directly destroying the life of the child by any process whatever, at the time of parturition, with the intention of saving the life of the mother. I will not examine this important matter in all its bearings at present; I mean to take it up later on in our course, and to lay before you the teachings of science on this subject, together with the principles on which they are based. For the present I will confine myself to the point we are treating just now, namely, the existence of a higher law than that of human tribunals, the superiority of the claims of natural to those of legal justice. Some might think, at first sight, that this needs no proof. In fact we are all convinced that human laws are often unjust, or, at least, very imperfect, and therefore they cannot be the ultimate test or fixed standard of right and wrong; yet the main argument advanced by one of the advocates of craniotomy rests upon the denial of a higher law, and the assertion of the authority of human tribunals as final in such matters.