I've written quite a bit about transgression and liminal spaces on my other blog, devoted to games. This is a topic where I think there's some overlap between games-as-play and sex-as-play. I've linked to the longer topics here, but let me recap quickly what I mean by those terms.
Transgression, and transgressive activities are those that break a social more. This is not a definition about what is and isn't legal, but what is considered by society to be moral. It's possible to step from normal space, to an alternate space where the transgression you're committing isn't immoral. It's still immoral from society's viewpoint, but it isn't in the new space or society. Those kinds of spaces are what I call liminal spaces.
Anytime we play, we set up rules about what is going to happen -- sometimes it's implicit and sometimes it's explicit -- and inside that playspace there is an understanding that some rules are only valid inside it, and within it, that when we step outside of it, the rules are gone or different. I also believe that all morally acceptable kink exists withing a play space like that.
I think it's easy to see that kink isn't really socially acceptable. It may be condoned by law, and more or less tolerated, but I don't think it'll ever be really acceptable (if it becomes so, then I think kink will move out along other extremes, in order to stay unacceptable. Why I think that is another post.) But really, something like "beating your spouse" that's not just morally unacceptable, it's probably illegal.
As kink practitioners, however, within our society we don't think it's necessarily wrong to beat your spouse, with one all-important proviso: consent. I don't know how much non-kinky people think about consent, but as a kinky person, that boundary line of kink defines the space I'm in. When I evoke it, with my partner, then we are in a different space where it's okay to do certain, negotiated things, and in fact, it's rather fun. We get something from that space as well, we become slightly different people -- yes, facets of our true selves, but with some changes in priority. For some people it's a dangerous space, where they are afraid, but safely so -- with the boundary there protecting them, and the ability to remove the boundary, and dissolve the space entirely.
With Girl, our original negotiations were detailed and specific, setting out the boundaries of our play. I pushed at them, because that's where the most fun is, but I stayed within them. Girl (and I) had, and have, the power to abolish a scene at any time if things aren't going the way we want. We did that some at the first -- it was as important for me to know that she would exert her boundaries as it was for her to know that I'd respect her exertion.
Thus we established the trust and now call up that space whenever we want to. We still negotiate at the edges of the space, and talk about where we'd like to go, and what we'd like to try. The boundaries are in flux, at one moment flexible, yet in another completely firm.
This liminal space lets us get into dom- and sub-space, where we let those aspects of our personality come to the fore, and take us over. I can be as cruel as that part of me desires. I don't need to control it myself, like we all do, as we've been trained by society. I have put in place another rule that will stop me if it's too much.
We leash our desires to the boundaries of the liminal space -- to consent itself -- always knowing that we can hit the safety switch and step away. Then it becomes safe to be slave to our desires, and that is where the wonderment of the experience comes from. Note, for instance, that other than 'beating my spouse' --which is just an example -- I've not said anything about the activities themselves, just that they are outside the society's norms and morality.
Consent is also key here. The liminal space of play doesn't exist without it. That means to me that rape cannot be BDSM. Spousal abuse cannot be BDSM. Torture cannot be BDSM. BDSM can look like all those things, but at its' core, surrounding and placing it in a different context, is the consent of all the participants.