I have been looking forward to this for a while. Would it be too mystical of me to say that I am being led to do this? My teacher is a second-generation (perhaps longer) practitioner who learned her craft as it was passed down to her. In other words, not one of these new-fangled New Agey types who learned it in a book. Think "Evelyn Paglini" (who has always impressed me). Why am I going in this direction? Well, I do believe that there are, for want of a better term, "forces" that are non-physical, or rather non-corporeal, but nonetheless real, conscious, and aware. Some of these forces are less than benevolent. I consider it due diligence to acknowledge the reality of these forces and protect myself from them.
On a side note, I just finished working in a Masonic degree. Freemasonry is, in my opinion, probably the best expression of a positive science of morality in the Western world. Most Americans associate "morality" with a Christian fundamentalist notion of do's and don'ts. But Freemasonry does not teach right or wrong; it instead teaches the serious student to examine his actions in the greater context of how they impact not only those immediately around him, but the society in which he lives. It's really a subtle and complex system of moral reflection that's largely lost in our culture.