In several voluminous works, Jennings developed the theory that the origin of all religion is to be sought in
phallic worship of the
Sun and
fire, which he described as "phallism." In addition to the works to which he affixed his own name, Jennings is thought by some researchers to have written a number of anonymous volumes in the privately printed "Nature Worship and Mystical Series" series, and possibly also to have written under the pseudonym "Sha Rocco." As Jennings made clear in several of his books, he used the word "phallic" in its non-gendered sense, meaning "having to do with the sexual organs"; thus he included worship of the female genitalia under the heading of "phallic." In later editions he reluctantly acceded to popular (although incorrect) usage and called his subject "phallicism." == Criticism ==