infamous Herod to defend himself against the future aggression, as he
imagined, of the new-born King of the Jews. A craniotomist would, no
doubt, feel insulted at being compared with Herod. And yet, if we
examine the matter closely, we shall find that the two massacres,
Herod's and the craniotomist's, could only be defended by the same plea,
that of necessity. "Necessity knows no law," writes Dr. Galloway, in his
defence of craniotomy, to which I referred in a former lecture. "The
same law," he writes in the "Medical Record" for July 27, 1895, "which
lies at the basis of Jurisprudence in this respect justifies the
sacrifice of the life of one person when actually necessary for the
preservation of the life of another, when the two are reduced to such
extremity that one or the other must die. This is the _necessitas non
habet legem_."

Did not Herod look on the matter just in that light? Expecting Christ to
be, not a spiritual, but a temporal ruler, as the Jewish nation supposed
at the time, he looked upon it as a case of necessity to sacrifice the
lives of the innocents for his own preservation. "Necessity knows no
law" was his principle. True, many had to die on that occasion to save
one; but then he was a king. Anyhow, their death was necessary, and
_necessitas non habet legem_; that settles it: Herod must not be blamed,
on that principle. It is not even certain that, cruel as he was, he
would have confessed, with the modern obstetrician, "I would as lief, if
it were necessary, kill an unborn child as a rat."

Such sentiments, revolting as they are, and a disgrace to civilization,
are the natural outcome of rash speculations about the first principles
of morality.

The principle "_Necessitas non habet legem_" has indeed a true and
harmless meaning when properly understood; it means that no law is
violated when a man does what he is physically necessitated to do, and
that no law can compel him to do more than he can do. Thus a disabled
soldier cannot be compelled to march on with his regiment; necessity
compels him to remain behind. In this sense the principle quoted is a
truism; hence its universal acceptance. Applying the same principle in a
wider sense, moralists agree that human law-givers do not, and in
ordinary circumstances cannot, impose obligations the fulfilment of
which requires extraordinary virtue. Even God Himself does not usually
exact of men the performance of positive heroic acts. But no such plea