One thing I like about Paganism, and particularly Wicca, is that rather than attempting to teach rules and ethics, it teaches wisdom. There’s really only one moral “rule” in Wicca, which is the Rede: “An it harm none do what ye will.” Most Wiccans interpret this to basically mean, do what you like as long as it doesn’t hurt anyone or anything. Which is a fairly liberal code in itself, but even then, some Wiccans do not follow it. Some, to quote Pirates of the Caribbean, see it as “more of a guideline than a code.”
But related to this is the Law of Three, also known as the Threefold Law. Held by some Wiccans, this is usually interpreted as, anything that one does to another person is returned on them threefold. So if a witch decides to curse a person, that curse will magically come back on them – but three times worse.
I don’t personally view the Threefold Law as a supernatural force. I interpret it as words of wisdom for life in general. In one way, it is simply a re-phrasing of the saying “to reap what you sow,” i.e. your actions, good or bad, always have consequences.
But the Threefold Law seems more often than not to apply specifically for negative things, especially inflicting pain or unhappiness on another person. In this case, I can also see how the Threefold Law could specifically be an expression of a phenomenon recognised by science.
Studies in neuroscience have shown that when it comes to conflict, be it physical or verbal, we usually underestimate how much we hurt our opponent. If we punch someone, it tends to be much harder than actually intended, inflicting more pain than we wanted to. This means that the other person retaliates with an even harder punch – but again, they too underestimate the force of the blow, and so on. This is why fights tend to escalate, simply because we do not realise just how much pain we are causing the other person.
It appears to be the case with non-physical conflict as well. When we say something mean to someone, they are often a lot more hurt by our words than we actually realise, and so in retaliation they come back and say something much more hurtful. What may start out as a simple criticism may be interpreted as a personal insult, resulting in a greater insult back, until the argument blows out of control and relationships break down.
This is what I think the Threefold Law is hinting at. Whenever we take action, especially if that action has the potential to cause harm or conflict with another person, we should expect a much greater reaction from the other person because we are probably causing a lot more harm than we actually intend. The Threefold Law therefore encourages us to think carefully before taking any action (be it magical or not), to thoroughly explore the possible repercussions of that action, and to take full responsibility over the results. I think this is a very sensible rule for anyone to follow, Wiccan or otherwise.