These words are taken from Italian Witchcraft by Raven Grimassi:
There is a vaporous, subtle and invisible quality to each of these things which are called the physical elements. The ancients have told us that all of creation was brought into being when Spirit drew the four elements unto itself. These elements are called Earth, Air, Fire and Water. And they are controlled by Spirit.
Each of these elements possess an etheric double. It is this essence which gives vitality or fertility to the physical object.
Just as the physical realms or matter contain their own forms of life, so too do the etheric realms. These entities have been personified as the many spirits and creatures of myth and legend. It is their activity which creates and maintains the vital essence within all matter.
The etheric powers of the elements also give potency to spells and works of Magick. It is within their realms that the Magickal powers ebb and flow. Thus are the spirits of the elements summoned to assist us.