Magick is power, and like any other form of power, it can be abused. Those who call themselves Witches adhere to (or should adhere to) a spiritual system that recognizes that we are connected to all other living things and cannot allow ourselves to fall prey to the abuse of power without suffering in kind.
Within the Craft we seek to live our lives in balance with all creation. This is what makes our magick its most potent. When we are in balance, our personal energies resonate with those of the universe; Being as one with it we can more easily draw on its resources. When we break that balance by sending negative energies out along the Wheel of Life, we set the motion of the wheel off kilter and its begins to wobble. Eventually the vibrations set up by that wobbling work their way back to us and we pay. It is an old metaphysical adage that like attracts like. Therefore, imbalance will attract imbalance.
The issue of Wiccan ethics is a mouthful to grasp. Until finding Paganism or Wicca, many people participated in religions that did not teach the concept of self-responsibility. The mainstream religions do not want you to think for yourself. They want you to sit in pews every Sunday while someone else dictates what you should and should not do. In many cases, the mere questioning of these edicts will get you punished by earning you disapproval. Pagan religions, in contrast, are religions of the individual. The ultimate decisions about what to think and how to behave rest within each of us. There is no execution or anyone to sit in judgement upon us. There is no one on whom to shift the blame when something goes wrong. Even if you are a part of a coven, you and only you are still responsible for the kind of energy you put out onto the wheel, since only you will bear the repurcutions of your choices.
There are a few rules that govern a Witch's actions, but there is one axiom almost universally recognized as our governing code of ethics. We call it the Wiccan Rede and it states:
As it harms none, do what you will!
This axiom is not only a Wiccan one, but is also referred to as the Golden Rule, and is a part of Christian doctrine (New Testament). This means we have the freedom to do anything we choose, magickally or personally, so long as we are sure our efforts and actions harm no one (not even ourselves). This "no one" includes animals and spirits, as well as people. We cannot take actions, even well intentioned ones, that infringe on the rights and wills of others. We may not attempt to manipulate or seek to gain power over someone, and we may not even perform positive magick for anyone without their express permission to do so.
Witches are not perfect, and we occassionally break this code of ethics either accidently or knowingly. When we do, we must be prepared to pay the consequences of our actions. In our spiritual system we have no Hell to be cast into for our punishment. Instead, we get our absolution in acceptance of what we know of as the Threefold Law. This tells us that all energies we send forth, either positive or negative, will return to us three times over. This is not a fear tactic, it is simply the natural result of living on the Wheel of Life. We cannot escape its turning. We must reap what we sow when the wheel turns our way.
Contrary to popular belief, the terms black magick and white magick are not used to describe magickal workings. These terms imply that all magick can be neatly categorized into neat columns of good and bad. Life is not that clear cut, and neither is magick. Somewhere along the line, someone coined the term gray magick to refer to that unclear state between good and bad. This actually isn't a very good term either, since it is often taken to refer to magick that is bad but that someone wants to do anyway hoping the bad element is small and the consequences will not amount to much. A common example of this is a Witch performing healing magick for a sick person who needs it, even though they do not give permission for it or are never asked. The rationale for doing so is that the Witch has the best interests of the sick person at heart and that since they are only sending out positive energy they can only get positive energy in return. WRONG! If the magick you perform is unwanted, no matter that you have positive intentions, what comes back to you will not be postitive. It is not acceptable under any circumstances to meddle in someone else's life. This is an infringement on someone's free will, and what you can only get in return is an infringement upon yours.
In spellwork, there is no black, white or gray...only raw magickal power. It has no moral character and we may draw upon it as we will. Like Pagan deities, we are beings who possess power. Sometimes we will use it wisely, sometimes we do not. If the Wiccan/Pagan path is the correct one for you, you will find the power of magick a humbling one, and not an ego-boosting one. Egotistical Witches usually find their powers turned against them in the end. To know that such a power is accessible to you, and to choose to honor it by handling it responsibly, is the most truly empowering mystery of the Craft. True and lasting power is not brandished like a weapon or pulled out when one wants to show off; It is simply part of who the magician is, and is worn with the ease of a second skin.
When first starting out in the Craft, you may step over the line of "Harm None", be braced for the backlash, but find that none comes. Because of this you may step over the line again, and still not receive your "punishment". However, it is important to realize that there is no instant bounce back. You may not even recognize life's little downturns as being a consequence of stepping over the line. Just trust that someday someone will come knocking on your door telling you its payback time. As you build on your skills and send greater energies onto the wheel, greater energies will return to you -- whether positive or negative.
SOURCES: Making Magick: What It is and How it Works, by Edain McCoy