Wow... quick replies. I'll try to answer them all in sum.

No, not magic necessarily, since I have no clue what that is.
But this WAS based on the occult, nothing remotely wiccan... I was thinking more along the lines of Evocation.(not Goetian, or the lesser keys of solomon) I am not wiccan. I think that it is silly that everything even pseudo-esoteric is pigeonholed like that. There are many older and vastly more respectable branches within the art of witchcraft than wicca. I have a personalized practice, not a religion. That would most likely make me pagan, or more accurately, mesopagan. Witchcraft would be what I prefer.

"However, I think you can put any fears to rest, since spirits cannot be summoned. This whole question strikes me as worrying about the morality of hiring Santa Clause to spy on a friend: it only works as a hypothetical situation, not one that could ever actually happen."

It is unnerving how simplistic that statement was, and a bit arrogant. You cannot prove or disprove any practice. YOu have only five senses, not enough to do what you pretend to do. And that is comprehending the boundlessly complex systems of our earth, and th cosmos themselves.
It is obvious you grasped little of what I was talking about. My apologies, that was my fault. There is no evil or good "spirit", the thought is cartoonish to me, really.
When I mentioned Evocation, I meant the form Crowley used the most, Egregore.
Which is basically a thoughtform entity composed of the symbiotic channeling of a common desire. To be blunt, personal thoughts influence this greatly.
So the question, in a nutshell.

Is it possible for fear to breed fear?
Is it just as negative?

"Aleister Crowley. Considered the Antichrist by some, founded the Thelema branch of witchcraft, had an angel of some kind. World's most famous occultist. Check him out on the Wiki."

He called himself "The Beast 666". A childhood nickname given by his mother. But Crowley being the man he was, allowed this rumor to surface commonly. A mistake, in my opinion.

"As for the other statement about his last words, were you tying it into this question somehow? Does it have something else to do with the defense magicks? I can't remember how he died, if that has anything to do with it."

Yes ::points up::
Not a big Crowley fan, nor magick. I do know that he died of a heart attack, and nobody heard his last words. They were a reflection, really, showing how the question sparked.