of remorse or self-reproach,
Claudius masked them successfully from the eyes of all. Hamlet's
instinctive dislike of his uncle was not shared by the members of the
Danish court. The "witchcraft of his wit," his "traitorous gifts,"
were powerful aids to Claudius, not only in the seduction of his
sister-in-law, but the perpetration of secret murder.

The case of the murder of King Duncan of Scotland by Macbeth and his
wife belongs to a different class of crime. It is a striking example of
dual crime, four instances of which are given towards the end of this
book. An Italian advocate, Scipio Sighele, has devoted a monograph to
the subject of dual crime, in which he examines a number of cases in
which two persons have jointly committed heinous crimes.(3) He finds
that in couples of this kind there is usually an incubus and a succubus,
the one who suggests the crime, the other on whom the suggestion works
until he or she becomes the accomplice or instrument of the stronger
will; "the one playing the Mephistophelian part of tempter, preaching
evil, urging to crime, the other allowing himself to be overcome by his
evil genius." In some cases these two roles are clearly differentiated;
it is easy, as in the case of Iago and Othello, Cassius and Brutus, to
say who prompted the crime. In others the guilt seems equally divided
and the original suggestion of crime to spring from a mutual tendency
towards the adoption of such an expedient. In Macbeth and his wife we
have a perfect instance of the latter class. No sooner have the witches
prophesied that Macbeth shall be a king than the "horrid image" of
the suggestion to murder Duncan presents itself to his mind, and, on
returning to his wife, he answers her question as to when Duncan is
to leave their house by the significant remark, "To-morrow--as he
proposes." To Lady Macbeth from the moment she has received her
husband's letter telling of the prophecy of the weird sisters, murder
occurs as a means of accomplishing their prediction. In the minds
of Macbeth and his wife the suggestion of murder is originally an
auto-suggestion, coming to them independently of each other as soon as
they learn from the witches that Macbeth is one day to be a king. To
Banquo a somewhat similar intimation is given, but no foul thought of
crime suggests itself for an instant to his loyal nature. What Macbeth
and his wife lack at first as thorough-going murderers is that complete
insensibility to taking