he stabbed him because
she "loved" him.

Gilles de Rais, who had fought beside Joan of Arc, is the classic
example of sadism in its extreme form, involving the murder of
youths and maidens. Bernelle considers that there is some truth
in the contention of Huysmans that the association with Joan of
Arc was a predisposing cause in unbalancing Gilles de Rais.
Another cause was his luxurious habit of life. He himself, no
doubt rightly, attached importance to the suggestions received in
reading Suetonius. He appears to have been a sexually precocious
child, judging from an obscure passage in his confessions. He was
artistic and scholarly, fond of books, of the society of learned
men, and of music. Bernelle sums him up as "a pious warrior, a
cruel and keen artist, a voluptuous assassin, an exalted mystic,"
who was at the same time unbalanced, a superior degenerate, and
morbidly impulsive. (The best books on Gilles de Rais are the
Abbe Bossard's _Gilles de Rais_, in which, however, the author,
being a priest, treats his subject as quite sane and abnormally
wicked; Huysmans's novel, _La-Bas_, which embodies a detailed
study of Gilles de Rais, and F.H. Bernelle's These de Paris, _La
Psychose de Gilles de Rais_, 1910.)

The opinion has been hazarded that the history of Gilles de Rais
is merely a legend. This view is not accepted, but there can be
no doubt that the sadistic manifestations which occurred in the
Middle Ages were mixed up with legendary and folk-lore elements.
These elements centered on the conception of the _werwolf_,
supposed to be a man temporarily transformed into a wolf with
blood-thirsty impulses. (See, e.g., articles "Werwolf" and
"Lycanthropy" in _Encyclopaedia Britannica_.) France, especially,
was infested with werwolves in the sixteenth century. In 1603,
however, it was decided at Bordeaux, in a trial involving a
werwolf, that lycanthropy was only an insane delusion. Dumas
("Les Loup-Garous," _Journal de Psychologie Normale et
Pathologique_, May-June, 1907) argues that the medieval werwolves
were sadists whose crimes were largely imaginative, though
sometimes real, the predecessor of the modern Jack the Ripper.
The complex nature of the elements making up the belief in the
werwolf is emphasized by Ernest Jones, _Der Alptraum_, 1912.

Related to the werwol