Mankind is constantly inclined to forget that what was once good does not remain good eternally. He goes along the old ways that once were good, long after they have become injurious to him; only through the greatest sacrifices and with untold suffering can he rid himself of this delusion, and discern that what was good once is now perhaps grown old and is good no longer. This is so in the little things as in the big.
The ways and customs of his childhood, once so sublimely good, he can barely lay aside even when their harmfulness has long since been proved. The same, only on a gigantic scale, is the case with historical changes of attitude. A general attitude corresponds with a religion, and changes of religion belong to the most painful moments in the world’s history.
In this respect our age has a blindness without parallel. We think we have only to declare an acknowledged form of faith to be incorrect or invalid, to become psychologically free of all the traditional effects of the Christian or Judaic religion.
We believe in enlightenment, as if an intellectual change of opinion had somehow a deeper influence on emotional processes, or indeed upon the unconscious. We entirely forget that the religion of the last two thousand years is a psychological attitude, a definite form and manner of adaptation to inner and outer experience, which molds a definite form of civilization; it has, thereby, created an atmosphere which remains wholly uninfluenced by any intellectual disavowal.
The intellectual change is, of course, symptomatically important as a hint of coming possibilities, but the deeper levels of the psyche continue for a long time to operate in the former attitude, in accordance with psychic inertia. In this way the unconscious has preserved paganism alive.
The ease with which the classic spirit springs again into life can be observed in the Renaissance. The readiness with which the vastly older primitive spirit reappears can be seen in our own time, even better perhaps than in any other historically known epoch. ~Carl Jung; Psychological Types; The Type Problem in Poetry