Say, for example, a man is consciously and consistently aroused by the thought of violently raping women. Now, I don't see how any reasonable person could ever consider rape a justifiable action (although there may be some extremely convoluted circumstances I'm not considering - I don't claim absolute knowledge, especially not on highly emotional issues). Suppose, also, that this man - in spite of his extremely anti-social sexual desires - is a well-adjusted gentleman, and has no intention whatsoever of committing a crime as heinous as rape against anyone.
Take a moment, if you need to, to internalize that concept - that a man could be sexually aroused by a criminal act but remain virtuous enough not to realistically want to commit it (separating fantasy from reality, as they ought to be). Now if this man rejects his sexual desires because of their violent and anti-social qualities, he is in essence demonstrating that he believes they are violent and anti-social, and is thus in a better position to receive sympathy from those who feel that way about the things he happens to be sexually interested in. After all, a man is not really in control of what happens to interest him sexually; but he can choose how he approaches those interests.
But what, then, of the man who decides that he is entitled to sexual satisfaction? Not, mind you, the man who goes out and commits rape because it turns him on, but the man who allows himself to enjoy rape fantasy - because he knows the difference between fantasy and reality and is capable of allowing the fantasy to excite him while simultaneously understanding that it is, in reality, an extremely undesirable act to commit, on account of entirely non-sexual reasons, if not sexual reasons as well (i.e., not everyone who is turned on by the idea of rape is turned on by actual rape - take another moment, if necessary, to internalize that one, too).
The essential question is this: to what extent is a man free to derive sexual satisfaction from ideas that disturb "prevailing public opinion"? We, as a collective culture, worry about people getting turned on by rape (among other things) because we fear it will encourage - if not the same people, then other, less morally guided individuals - to commit rape, in the belief that if society allows us to think about it and talk about it and fantasize about it - especially in positive terms - then society will be more forgiving (if not downright accepting) of those who commit it.
Isn't this pretty crazy, though? Does the human brain not have the capacity to differentiate between what are good fantasies and bad realities? And if a fraction (could it really be a majority?) of the human population is lacking this capability, is it the responsibility of the rest of us to curb our speech, essentially punishing ourselves for the infirmities of our neighbors? Frankly, I think the hysteria arises from a misunderstanding of the role of fantasy - which is not necessarily a blueprint for reality - but especially the nature of sexual fantasy.
I don't exactly blame society for this, because our bias on the way we view sex prevents us from learning and understanding a whole lot about human sexuality. I do, however, blame society for not doing more to combat this anti-sexual prejudice. As a human being with a sexual libido, and no driving force (at least not since I left my "abstinence is grand!" sex ed long behind) to withhold my curiosity about sexual desire, I've embarked on the exciting adventure of finding out what it is that turns me on. And to my surprise, though I've always considered myself to be vanilla (and still do, for the most part), I've found that I can be turned on by some pretty twisted things (as I imagine most people - if given the chance - could, even if it's not what they prefer).
A lot of such things I wouldn't even want (let alone consider) to do in reality - and not just because they're not practical, but because they're the kind of fantasies that are just fantasies, ideas that appeal because they aren't bound to the laws of reality. And while you can certainly argue that my modesty and my chastity has gone out the window (good riddance!), when you start talking about "morals" - regardless of my beliefs about sex, I am not the sort of selfish, sociopathic person who hurts, deceives, or takes advantage of other people for my own gain, sexual or otherwise.
I can revel in sometimes (but certainly not always) sick sexual fantasies and it doesn't make me a rampaging monster. What it does, however, is increase the amount of pleasure I experience in life. And given how shitty life can be - especially to someone who wasn't popular in high school, didn't get a well-paying job, marry a beautiful wife, have healthy kids, and find a sturdy house for them to live in - that's a goddamn blessing!
And if anyone should be on board with a sex positive, "don't be ashamed of what turns you on" approach, it's the BDSM community, who is used to having strange and often anti-social (sometimes violent) sexual desires and being demonized and misunderstood for it. But there always seems to be a caveat - "our desires may be sick, but I understand them so I know they're okay - but yours, yours I don't understand, and they just seem wrong!" The sadomasochists criticize the bestials who criticize the necrophiles, and every one of them criticizes pedophiles.
I'm not saying everything is always sunshine and rainbows in sexland, and that nobody ever engages in dangerous or criminal acts, motivated by sexual desire, I just want to develop an approach towards sex that works across the board, with noone left out. An approach that says, it doesn't matter what turns you on, you can be human and you can be a good person and you can find sexual satisfaction, so long as you're not harming anyone (where 'harm' is differentiated from 'hurt', which a person might be aroused by receiving). You can talk about consent, but if you define it in such a way as to deny it to a broad class (whether of persons or non-persons) on principle, then it's not really about consent, it's about your personal morals.
One of my fundamental rules for sex would be that noone should feel ashamed of what turns them on - no one. That is part of the truth about beauty. What exists in your head - what makes you feel good, and especially what you find to be appealing, regardless of who or how many people vehemently disagree, can never be "wrong". It's what you do to other people (and your treatment of non-persons) that matters. Thoughts are not actions, and fantasies are not realities. It is not our desires that determine who we are - it is our behaviors.