that the intensity of a passion increases, and vice versa. The problem
cannot be solved in this way. There are passions which may rise to the
highest degree of intensity without reducing the responsibility. For
instance, is one who murders from motives of revenge a passionate
criminal who must be excused?

The classic school of criminology says "No," and for my part I agree
with them. Francesco Carrara says: "There are blind passions, and others
which are reasonable. Blind passions deprive one of free will,
reasonable ones do not. Blind and excusable passions are fear, honor,
love, reasonable and inexcusable ones are hatred and revenge." But how
so? I have studied murderers who killed for revenge and who told me that
the desire for revenge took hold of them like a fever, so that they
"forgot even to eat." Hate and revenge can take possession of a man to
such an extent that he becomes blind with passion. The truth is that
passion must be considered not so far as its violence or quantity are
concerned, but rather as to its quality. We must distinguish between
social and anti-social passion, the one favoring the conditions of life
for the species and collectivity, the other antagonistic to the
development of the collectivity. In the first case, we have love,
injured honor, etc, which are passions normally useful to society, and
aberrations of which may be excused more or less according to individual
cases. On the other hand, we have inexcusable passions, because their
psychological tendency is to antagonize the development of society. They
are antisocial, and cannot be excused, and hate and revenge are among
them.

The positive school therefore admits that a passion is excusable, when
the moral sense of a man is normal, when his past record is clear, and
when his crime is due to a social passion, which makes it excusable.