Of the Supernatural and Modern Half-Believers

"...Student of folklore Christina Hole describes the half-belief when she notes that while '... most people would hotly deny that they believe in magic, many frequently resort to it in luck-bringing rites, precautionary words or actions against misfortune.' Most of us may know a person (or may be a person) who, after asserting that a certain rather unpleasant occurrence has never happened, will then 'knock on wood' ... --probably a relic of the ancient belief that woods such as elder and oak have magical, protective powers.
          The modern knocker-on-wood may do so with a mocking laugh, or some other outward disclaimer, in case his associates (or employer or wife) suspect his maturity and sanity. Nevertheless, he performs the ritual. He may also carry a rabbit's foot, or similar 'lucky charm, ; though he may deny that he believes that it contains any magical power to bring him good luck. But he makes sure, when he goes lout, that he has it with him. He is a half-believer; he is trying to hedge his bets.
          Incidentally, some of the superstitious magical practices we still indulge in are often not recognized as such. We know it is 'foolish' to believe that a broken mirror will bring bad luck (one's mirror image supposedly contains one's soul, and breaking the mirror prevents the soul's return to the body). We may not know that the enjoyable modern ceremony of throwing rice (or its up-to-date substitute, confetti) over a newly married couple is in fact an ancient fertility ritual--the scattering of products of plentiful nature being a symbolic and magical act intended to make the marriage equally fertile and productive."

Douglas Hill and Pat Williams, 1965, 20-21

The Supernatural