In all aspects of life, through the animal kingdom to humanity, it is the only source and cause of generation; and that of itself discloses to the thinker its importance. The great teachers of humanity have therefore wished man to look upon every expression of passion as sacred; and as most sacred of all that passion which exists in the love of the sexes for each other. The desire to make sex passion a most sacred thing is seen in the teaching of Shiva; and the origin of phallic worship lay in the desire to raise in the sight of humanity the sacredness of passion, and to free it from the shame and contempt with which men viewed it.