White magick may be used for magical protection, especially against malevolent occult and psychic influences (read that "psychic attack"). It is perfectly ethical to use white magick for protection of yourself in this manner, since we may assume that anything which would try to attack you is acting in a malevolent manner. Therefore it is appropriate to use good magick (white magick) for protection against evil magick (aversive magick). It is for the better good to do so.
Generally, the most appropriate form used for magical protection is the invocation of a magical shield or barrier. This may be visualized as a white light or bubble which surrounds you. It is not necessary to act in an aggressive manner about this, only to block aversive influences. It is even possible for experienced white magicians to *transform* malevalent magical energy into constructive, positive energy, by changing it's purpose. By changing the nature of the psychic force involved in this way, it may be used for healing, for example. For additional suggestins on protection against psychic attack , see this article, which I wrote years ago.